Mercruiser Service Manual #25 GM V6 1998 - 2001

Number 25

Printed in U.S.A. 90-861328--1 1199 1999, Mercury Marine

GM V-6262 CID (4.3L)

MARINE ENGINES

��

��

90-

i

MerCruiser #25 GM V-6262 CID (4.3L)

90-861328--1

MerCruiser #25 GM V-6262 CID (4.3L)

90-861328--1

90-861328--1 NOVEMBER 1999 Page i

Notice

Throughout this publication, “Dangers,” “Warnings” and “Cautions” (accompanied by the In-ternational HAZARD Symbol ) are used to alert the mechanic to special instructions con-cerning a particular service or operation that may be hazardous if performed incorrectly orcarelessly. OBSERVE THEM CAREFULLY!

These “Safety Alerts” alone cannot eliminate the hazards that they signal. Strict complianceto these special instructions when performing the service, plus “Common Sense” operation,are major accident prevention measures.

DANGERDANGER - Immediate hazards which WILL result in severe personal injury or death.

WARNINGWARNING - Hazards or unsafe practices which COULD result in severe personal in-jury or death.

CAUTIONHazards or unsafe practices which could result in minor personal injury or productor property damage.

Notice to Users of This Manual

This service manual has been written and published by the Service Department of MercuryMarine to aid our dealers’ mechanics and company service personnel when servicing theproducts described herein.

It is assumed that these personnel are familiar with the servicing procedures of these prod-ucts, or like or similar products manufactured and marketed by Mercury Marine, that theyhave been trained in the recommended servicing procedures of these products which in-cludes the use of mechanics’ common hand tools and the special Mercury Marine or recom-mended tools from other suppliers.

We could not possibly know of and advise the service trade of all conceivable proceduresby which a service might be performed and of the possible hazards and/or results of eachmethod. We have not undertaken any such wide evaluation. Therefore, anyone who usesa service procedure and/or tool, which is not recommended by the manufacturer, first mustcompletely satisfy himself that neither his nor the products safety will be endangered by theservice procedure selected.

All information, illustrations and specifications contained in this manual are based on thelatest product information available at the time of publication. As required, revisions to thismanual will be sent to all dealers contracted by us to sell and/or service these products.

It should be kept in mind, while working on the product, that the electrical system and ignitionsystem are capable of violent and damaging short circuits or severe electrical shocks. Whenperforming any work where electrical terminals could possibly be grounded or touched bythe mechanic, the battery cables should be disconnected at the battery.

Any time the intake or exhaust openings are exposed during service they should be coveredto protect against accidental entrance of foreign material which could enter the cylinders andcause extensive internal damage when the engine is started.

Page ii 90-861328--1 NOVEMBER 1999

It is important to note, during any maintenance procedure replacement fasteners must havethe same measurements and strength as those removed. Numbers on the heads of the met-ric bolts and on the surfaces of metric nuts indicate their strength. American bolts use radiallines for this purpose, while most American nuts do not have strength markings. Mis-matched or incorrect fasteners can result in damage or malfunction, or possibly personalinjury. Therefore, fasteners removed should be saved for reuse in the same locations when-ever possible. Where the fasteners are not satisfactory for re-use, care should be taken toselect a replacement that matches the original.

We reserve the right to make changes to this manual without prior notification.

Refer to dealer service bulletins for other pertinent information concerning the productsdescribed in this manual.

Engine Mechanical ComponentsMany of the engine mechanical components are designed for marine applications. Unlikeautomotive engines, marine engines are subjected to extended periods of heavy loadand wide-open-throttle operation and, therefore, require heavy-duty components. Specialmarine engine parts have design and manufacturing specifications which are required toprovide long life and dependable performance. Marine engine parts also must be able toresist the corrosive action of salt or brackish water that will rust or corrode standard automo-tive parts within a short period of time.

Failure to use recommended Quicksilver service replacement parts can result in poor en-gine performance and/or durability, rapid corrosion of parts subjected to salt water andpossibly complete failure of the engine.

Use of parts other than recommended service replacement parts, will void the warranty onthose parts which are damaged as a result of the use of other than recommended replace-ment parts.

Replacement Parts

WARNINGElectrical, ignition and fuel system components on MerCruiser Engines and Stern-drives are designed and manufactured to comply with U.S. Coast Guard Rulesand Regulations to minimize risks of fire or explosion.

Use of replacement electrical, ignition or fuel system components, which do notcomply to these rules and regulations, could result in a fire or explosion hazard andshould be avoided.

When servicing the electrical, ignition and fuel systems, it is extremely importantthat all components are properly installed and tightened. If not, any electrical or ig-nition component opening would permit sparks to ignite fuel vapors from fuel sys-tem leaks, if they existed.

1

2

3

4

5

6

7

8

9

Important Information

Removal and Installation

Engine

Electrical Systems

Fuel Systems

Cooling System

Exhaust System

Drives

Power Steering System

90-861328--1 NOVEMBER 1999 Page iii

Service Manual Outline

Section 1 - Important InformationA - General InformationB - MaintenanceC - Troubleshooting

Section 2 - Removal and InstallationA - MCM Models

Section 3 - EngineA - 262 CID / 4.3L Engines

Section 4 - Electrical SystemsA - Starting SystemB - Ignition SystemC - Charging SystemD - InstrumentationE - Wiring Diagrams

Section 5 - Fuel SystemsA - Fuel Delivery System For Carbureted EnginesB - Mercarb 2 Barrel CarburetorC - Weber 4 Barrel CarburetorD - SAV1 Emission Fuel System With Weber CarburetorE - Fuel Delivery System For Electronic Fuel InjectionF - Fuel Injection Descriptions And System OperationG - Fuel Injection Disassembly And ReassemblyH - Fuel Injection System TroubleshootingI - Diagnostics

Section 6 - Cooling SystemA - Seawater Cooled ModelsB - Closed Cooled Models

Section 7 - Exhaust SystemA - GeneralB - Manifolds, Elbows and RisersC - Collectors

Section 8 - DrivesA - Drive Shaft Models

Section 9 - Power Steering SystemA - Pump and Related Components

Page iv 90-861328--1 NOVEMBER 1999

Table of Contents

IMPORTANT INFORMATIONSection 1A - General Information

Introduction 1A-2. . . . . . . . . . . . . . . . . . . . . . . . . How to Use This Manual 1A-2. . . . . . . . . . . . .

Page Numbering 1A-2. . . . . . . . . . . . . . . . . How to Read a Parts Manual 1A-3. . . . . . . . . Directional References 1A-4. . . . . . . . . . . . . . . Engine Rotation 1A-4. . . . . . . . . . . . . . . . . . . . . Engine Serial Number Location 1A-5. . . . . . .

Propeller Information 1A-5. . . . . . . . . . . . . . . . Water Testing New Engines 1A-6. . . . . . . . . . Boat and Engine Performance 1A-6. . . . . . . .

Boat Bottom 1A-6. . . . . . . . . . . . . . . . . . . . . Marine Fouling 1A-7. . . . . . . . . . . . . . . . . . . Weight Distribution 1A-8. . . . . . . . . . . . . . . . Water in Boat 1A-9. . . . . . . . . . . . . . . . . . . . Elevation and Climate 1A-9. . . . . . . . . . . . .

Section 1B - MaintenanceTools 1B-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Lubricants / Sealants / Adhesives 1B-2. . . . . Maintenance Schedules 1B-3. . . . . . . . . . . . . .

Maintenance Intervals 1B-3. . . . . . . . . . . . . Gas Sterndrive 1B-3. . . . . . . . . . . . . . . . . . . . . .

Routine Maintenance * 1B-3. . . . . . . . . . . . Scheduled Maintenance * 1B-4. . . . . . . . . .

Engine and Tune-Up Specifications 1B-5. . . . MCM (Sterndrive) 1B-5. . . . . . . . . . . . . . . . .

Fluid Capacities 1B-6. . . . . . . . . . . . . . . . . . . . . Sterndrive Engines 1B-6. . . . . . . . . . . . . . . Sterndrives 1B-6. . . . . . . . . . . . . . . . . . . . . .

20-Hour Break-In Period 1B-7. . . . . . . . . . . . . After Break-in Period 1B-7. . . . . . . . . . . . . . . . End of First Season Checkup 1B-7. . . . . . . . . Specifications 1B-8. . . . . . . . . . . . . . . . . . . . . . .

Fuel Recommendations 1B-8. . . . . . . . . . . Test For Alcohol Content In Gasoline 1B-10

Power Steering Fluid 1B-10. . . . . . . . . . . . . . . . Coolant for Closed Cooling System 1B-10. . . . Crankcase Oil 1B-11. . . . . . . . . . . . . . . . . . . . . .

Overfilled Crankcase Oil 1B-11. . . . . . . . . . . Checking Engine Oil Level / Filling 1B-12. .

Changing Oil and Filter 1B-12. . . . . . . . . . . . . . . Changing Water Separating Fuel Filter 1B-13. Power Steering System 1B-15. . . . . . . . . . . . . .

Checking Fluid Level 1B-15. . . . . . . . . . . . . . Engine Cold 1B-15. . . . . . . . . . . . . . . . . . . . . Filling and Bleeding 1B-16. . . . . . . . . . . . . . .

Closed Cooling System 1B-17. . . . . . . . . . . . . . Checking Coolant Level 1B-17. . . . . . . . . . . Flushing System 1B-18. . . . . . . . . . . . . . . . .

Lubrication 1B-20. . . . . . . . . . . . . . . . . . . . . . . . . Throttle Cable 1B-20. . . . . . . . . . . . . . . . . . . . Shift Cable 1B-20. . . . . . . . . . . . . . . . . . . . . . . Engine Coupler / U-Joint Shaft Splines 1B-21. . . . . . . . . . . . . Sterndrive Drive Shaft Extension Models 1B-22. . . . . . . . . . .

Cleaning Flame Arrestor 1B-22. . . . . . . . . . . . . Top Mounted Flame Arrestor 1B-23. . . . . . .

Serpentine Drive Belt 1B-23. . . . . . . . . . . . . . . . Component Location 1B-23. . . . . . . . . . . . . .

Serpentine Belt Routing 1B-24. . . . . . . . . . . . . . S/N 0L619083 and Below 1B-24. . . . . . . . . . S/N 0L619084 and Above 1B-25. . . . . . . . . Inspection 1B-26. . . . . . . . . . . . . . . . . . . . . . . Replacing and/or Adjusting Tension 1B-26.

Ignition Timing 1B-27. . . . . . . . . . . . . . . . . . . . . . Thunderbolt V Models 1B-27. . . . . . . . . . . . . EFI 1B-28. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Cold Weather or Extended Storage 1B-29. . . . Precautions 1B-29. . . . . . . . . . . . . . . . . . . . . . Power Package Layup 1B-31. . . . . . . . . . . . Draining Instructions 1B-33. . . . . . . . . . . . . . Draining Sterndrive 1B-38. . . . . . . . . . . . . . . Recommissioning 1B-39. . . . . . . . . . . . . . . . .

90-861328--1 NOVEMBER 1999 Page v

Section 1C - TroubleshootingPrecautions 1C-2. . . . . . . . . . . . . . . . . . . . . . . . Used Spark Plug Analysis 1C-3. . . . . . . . . . . .

Normal Condition 1C-3. . . . . . . . . . . . . . . . . Chipped Insulator 1C-3. . . . . . . . . . . . . . . . . Wet Fouling (Oil Deposits) 1C-4. . . . . . . . . Cold Fouling 1C-4. . . . . . . . . . . . . . . . . . . . . Overheating 1C-4. . . . . . . . . . . . . . . . . . . . . High Speed Glazing 1C-5. . . . . . . . . . . . . . . Scavenger Deposits 1C-5. . . . . . . . . . . . . . Pre-Ignition Damage 1C-5. . . . . . . . . . . . . . Reversed Coil Polarity 1C-6. . . . . . . . . . . . . Splashed Deposits 1C-6. . . . . . . . . . . . . . . . Mechanical Damage 1C-6. . . . . . . . . . . . . .

Poor Boat Performance and/or Poor Maneuverability 1C-7. . . . . . . . . . . . . . . . Improper Full Throttle Engine RPM 1C-8. . . .

RPM Too High 1C-8. . . . . . . . . . . . . . . . . . . RPM Too Low 1C-8. . . . . . . . . . . . . . . . . . . .

Engine Cranks Over But Will Not Start Or Starts Hard 1C-9I. . . . . . . . . . . . . . . . . . . . . . mportant Information 1C-9. . . . . . . . . . . . . . . . .

Thunderbolt V Ignition (No Spark) 1C-10. . . Testing Thunderbolt V Ignition System 1C-10Fuel System Rich 1C-11. . . . . . . . . . . . . . . . . Fuel System Lean 1C-11. . . . . . . . . . . . . . . . Miscellaneous 1C-11. . . . . . . . . . . . . . . . . . . .

Engine Will Not Crank Over 1C-12. . . . . . . . . . . Charging System Inoperative 1C-12. . . . . . . . . Noisy Alternator 1C-13. . . . . . . . . . . . . . . . . . . . . Instrumentation Malfunction 1C-13. . . . . . . . . . Radio Noise 1C-13. . . . . . . . . . . . . . . . . . . . . . . .

Poor Fuel Economy 1C-14. . . . . . . . . . . . . . . . . Engine Runs Poorly at Idle 1C-14. . . . . . . . . . . Engine Runs Poorly At High RPM 1C-15. . . . . Engine Acceleration Is Poor 1C-16. . . . . . . . . . Troubleshooting with Vacuum Gauge 1C-16. . Engine Noise 1C-17. . . . . . . . . . . . . . . . . . . . . . .

Important Information 1C-17. . . . . . . . . . . . . Valve Cover Area 1C-17. . . . . . . . . . . . . . . . . Cylinder Area 1C-18. . . . . . . . . . . . . . . . . . . . Camshaft Area 1C-18. . . . . . . . . . . . . . . . . . . Crankshaft Area 1C-19. . . . . . . . . . . . . . . . . . Miscellaneous 1C-20. . . . . . . . . . . . . . . . . . . .

Oil Pressure 1C-21. . . . . . . . . . . . . . . . . . . . . . . . Miscellaneous 1C-21. . . . . . . . . . . . . . . . . . . . Low Oil Pressure 1C-22. . . . . . . . . . . . . . . . . High Oil Pressure 1C-22. . . . . . . . . . . . . . . . .

Excessive Oil Consumption 1C-23. . . . . . . . . . . Water In Engine 1C-24. . . . . . . . . . . . . . . . . . . . .

Important Information 1C-24. . . . . . . . . . . . . Water on Top of Pistons 1C-25. . . . . . . . . . . Water in Crankcase Oil 1C-25. . . . . . . . . . . .

Engine Overheats 1C-26. . . . . . . . . . . . . . . . . . . Mechanical 1C-26. . . . . . . . . . . . . . . . . . . . . .

Engine Overheats 1C-27. . . . . . . . . . . . . . . . . . . Cooling System 1C-27. . . . . . . . . . . . . . . . . . Insufficient Water Flow from Belt Driven Seawater Pickup Pump 1C-28.

Power Steering 1C-29. . . . . . . . . . . . . . . . . . . . . Poor, Erratic or No Assist 1C-29. . . . . . . . . . Noisy Pump 1C-30. . . . . . . . . . . . . . . . . . . . . . Fluid Leaks 1C-30. . . . . . . . . . . . . . . . . . . . . .

REMOVAL AND INSTALLATIONSection 2A - MCM Models

Torque Specifications 2A-2. . . . . . . . . . . . . . . . Tools 2A-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Lubricants / Sealants / Adhesives 2A-2. . . . . Removal 2A-3. . . . . . . . . . . . . . . . . . . . . . . . . . . Installation and Alignment 2A-5. . . . . . . . . . . .

Engine Connections 2A-10. . . . . . . . . . . . . . Electrical Connections 2A-11. . . . . . . . . . . . . Mercathode Connections 2A-12. . . . . . . . . . Shift Cable Installation 2A-12. . . . . . . . . . . . Power Steering Connections 2A-12. . . . . . . Fuel Supply Connections 2A-13. . . . . . . . . . Throttle Cable Installation and Adjustment 2A-14. . . . . . . . . . . . . . . . . . . . . .

Page vi 90-861328--1 NOVEMBER 1999

ENGINESection 3A - 262 cid (4.3L) Engines

Torque Specifications 3A-2. . . . . . . . . . . . . . . Lubricants / Sealants / Adhesives 3A-4. . . . . Tools 3A-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Specifications 3A-6. . . . . . . . . . . . . . . . . . . . . . . General 3A-11. . . . . . . . . . . . . . . . . . . . . . . . . . . . Bearing Failures 3A-14. . . . . . . . . . . . . . . . . . . . Piston Failures 3A-16. . . . . . . . . . . . . . . . . . . . . .

Pre-Ignition 3A-16. . . . . . . . . . . . . . . . . . . . . . Detonation 3A-17. . . . . . . . . . . . . . . . . . . . . . .

Engine Mounts 3A-19. . . . . . . . . . . . . . . . . . . . . . Rocker Arm Cover 3A-20. . . . . . . . . . . . . . . . . . .

Removal 3A-20. . . . . . . . . . . . . . . . . . . . . . . . Installation 3A-20. . . . . . . . . . . . . . . . . . . . . . .

Intake Manifold 3A-21. . . . . . . . . . . . . . . . . . . . . Removal 3A-21. . . . . . . . . . . . . . . . . . . . . . . . Cleaning and Inspection 3A-23. . . . . . . . . . . Installation 3A-23. . . . . . . . . . . . . . . . . . . . . . .

Rocker Arm / Push Rod 3A-27. . . . . . . . . . . . . . Removal 3A-27. . . . . . . . . . . . . . . . . . . . . . . . Cleaning and Inspection 3A-28. . . . . . . . . . . Installation 3A-28. . . . . . . . . . . . . . . . . . . . . . .

Hydraulic Roller Valve Lifters 3A-29. . . . . . . . . Locating Noisy Lifters 3A-30. . . . . . . . . . . . . Removal 3A-31. . . . . . . . . . . . . . . . . . . . . . . . Cleaning and Inspection 3A-34. . . . . . . . . . . Installation 3A-34. . . . . . . . . . . . . . . . . . . . . . .

Valve Stem Oil Seal / Valve Spring 3A-36. . . . Removal - Head Installed 3A-36. . . . . . . . . . Valve Assembly (Exploded View) 3A-38. . . Installation - Head Installed 3A-39. . . . . . . .

Cylinder Head 3A-40. . . . . . . . . . . . . . . . . . . . . . Removal 3A-40. . . . . . . . . . . . . . . . . . . . . . . . Cleaning and Inspection 3A-42. . . . . . . . . . . Installation 3A-43. . . . . . . . . . . . . . . . . . . . . . .

Cylinder Head and Valve Conditioning 3A-47. Disassembly 3A-47. . . . . . . . . . . . . . . . . . . . . Cleaning 3A-47. . . . . . . . . . . . . . . . . . . . . . . . Inspection 3A-48. . . . . . . . . . . . . . . . . . . . . . . Valve Guide Bore Repair 3A-49. . . . . . . . . . Valve Springs - Checking Tension 3A-50. . . Valve Seat Repair 3A-50. . . . . . . . . . . . . . . . Valve Grinding 3A-51. . . . . . . . . . . . . . . . . . . Reassembly 3A-52. . . . . . . . . . . . . . . . . . . . .

Dipstick Specifications 3A-55. . . . . . . . . . . . . . . Oil Pan 3A-56. . . . . . . . . . . . . . . . . . . . . . . . . . . .


Oil Pump 3A-57. . . . . . . . . . . . . . . . . . . . . . . . . . . Removal 3A-57. . . . . . . . . . . . . . . . . . . . . . . . Disassembly 3A-58. . . . . . . . . . . . . . . . . . . . . Cleaning and Inspection 3A-58. . . . . . . . . . . Reassembly 3A-58. . . . . . . . . . . . . . . . . . . . . Installation 3A-59. . . . . . . . . . . . . . . . . . . . . . .

Torsional Damper 3A-59. . . . . . . . . . . . . . . . . . . Removal 3A-59. . . . . . . . . . . . . . . . . . . . . . . . Installation 3A-60. . . . . . . . . . . . . . . . . . . . . . .

Crankcase Front Cover Oil Seal 3A-61. . . . . . . Crankcase Front Cover 3A-62. . . . . . . . . . . . . .

Removal 3A-62. . . . . . . . . . . . . . . . . . . . . . . . Cleaning and Inspection 3A-63. . . . . . . . . . . Installation 3A-63. . . . . . . . . . . . . . . . . . . . . . .

Flywheel 3A-64. . . . . . . . . . . . . . . . . . . . . . . . . . . Removal 3A-64. . . . . . . . . . . . . . . . . . . . . . . . Inspection 3A-64. . . . . . . . . . . . . . . . . . . . . . . Installation 3A-65. . . . . . . . . . . . . . . . . . . . . . .

Rear Main Oil Seal 3A-66. . . . . . . . . . . . . . . . . . Removal 3A-66. . . . . . . . . . . . . . . . . . . . . . . . Cleaning and Inspection 3A-67. . . . . . . . . . . Installation 3A-67. . . . . . . . . . . . . . . . . . . . . . .

Rear Main Oil Seal Retainer 3A-68. . . . . . . . . . Removal 3A-68. . . . . . . . . . . . . . . . . . . . . . . . Cleaning and Inspection 3A-68. . . . . . . . . . . Installation 3A-68. . . . . . . . . . . . . . . . . . . . . . .

Main Bearings 3A-69. . . . . . . . . . . . . . . . . . . . . . Inspection 3A-69. . . . . . . . . . . . . . . . . . . . . . . Replacement 3A-71. . . . . . . . . . . . . . . . . . . . .

Connecting Rod Bearings 3A-74. . . . . . . . . . . . Inspection and Replacement 3A-74. . . . . . .

Connecting Rod / Piston Assembly 3A-76. . . . Removal 3A-76. . . . . . . . . . . . . . . . . . . . . . . . Disassembly 3A-77. . . . . . . . . . . . . . . . . . . . . Cleaning and Inspection 3A-78. . . . . . . . . . . Reassembly 3A-80. . . . . . . . . . . . . . . . . . . . . Installation 3A-82. . . . . . . . . . . . . . . . . . . . . . .

Crankshaft 3A-84. . . . . . . . . . . . . . . . . . . . . . . . . Removal 3A-84. . . . . . . . . . . . . . . . . . . . . . . . Cleaning and Inspection 3A-86. . . . . . . . . . . Installation 3A-87. . . . . . . . . . . . . . . . . . . . . . .

Timing Chain and Sprocket 3A-88. . . . . . . . . . . Exploded View 3A-88. . . . . . . . . . . . . . . . . . . Removal 3A-88. . . . . . . . . . . . . . . . . . . . . . . . Cleaning and Inspection 3A-89. . . . . . . . . . . Installation - Timing Chain 3A-89. . . . . . . . .

Crankshaft Sprocket 3A-89. . . . . . . . . . . . . . . . . Removal 3A-89. . . . . . . . . . . . . . . . . . . . . . . . Installation 3A-89. . . . . . . . . . . . . . . . . . . . . . . Checking Timing Chain Deflection 3A-90. .

Balance Shaft / Gears 3A-91. . . . . . . . . . . . . . . Removal 3A-91. . . . . . . . . . . . . . . . . . . . . . . . Cleaning and Inspection 3A-94. . . . . . . . . . . Installation 3A-94. . . . . . . . . . . . . . . . . . . . . . .

Camshaft 3A-96. . . . . . . . . . . . . . . . . . . . . . . . . . Measuring Lobe Lift 3A-96. . . . . . . . . . . . . . . Removal 3A-97. . . . . . . . . . . . . . . . . . . . . . . . Inspection 3A-98. . . . . . . . . . . . . . . . . . . . . . . Installation 3A-98. . . . . . . . . . . . . . . . . . . . . . .

Camshaft Bearings 3A-99. . . . . . . . . . . . . . . . . . Removal 3A-99. . . . . . . . . . . . . . . . . . . . . . . . Inspection 3A-100. . . . . . . . . . . . . . . . . . . . . . . Installation 3A-100. . . . . . . . . . . . . . . . . . . . . . .

Cylinder Block 3A-101. . . . . . . . . . . . . . . . . . . . . . Cleaning and Inspection 3A-101. . . . . . . . . . .

Oil Filter By-Pass Valve 3A-105. . . . . . . . . . . . . . Inspection and/or Replacement 3A-105. . . . .

Remote Oil Filter 3A-106. . . . . . . . . . . . . . . . . . . . Inspection and/or Replacement 3A-106. . . . .

90-861328--1 NOVEMBER 1999 Page vii

Section 4A - Starting SystemsIdentification 4A-2. . . . . . . . . . . . . . . . . . . . . . . . Replacement Parts Warning 4A-2. . . . . . . . . . General Precautions 4A-2. . . . . . . . . . . . . . . . . Starting System Components 4A-3. . . . . . . . . Positive Current Flow 4A-4. . . . . . . . . . . . . . . . Battery 4A-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Battery Cable Recommendations 4A-4. . . Maintenance 4A-6. . . . . . . . . . . . . . . . . . . . . Testing 4A-7. . . . . . . . . . . . . . . . . . . . . . . . . . Storage 4A-7. . . . . . . . . . . . . . . . . . . . . . . . . Charging Guide 4A-8. . . . . . . . . . . . . . . . . . How Temperature Affects Battery Power 4A-8. . . . . . . . . . . . . . . . . . .

Standard Starter Slave Solenoid 4A-9. . . . . . Identification 4A-9. . . . . . . . . . . . . . . . . . . . . Standard Type Slave Solenoid 4A-9. . . . . Testing / Replacement 4A-9. . . . . . . . . . . . . Installation 4A-10. . . . . . . . . . . . . . . . . . . . . . .

Permanent Magnet - Gear Reduction(PG260F1) Starter Motor 4A-10. . . . . . . . . . . . .

Starter Specifications 4A-10. . . . . . . . . . . . . Torque Specifications 4A-10. . . . . . . . . . . . . Lubricants / Sealants 4A-10. . . . . . . . . . . . . . Description 4A-11. . . . . . . . . . . . . . . . . . . . . .

PG260F1 Exploded View 4A-12. . . . . . . . . . . . . Solenoid Switch 4A-13. . . . . . . . . . . . . . . . . . . . .

Periodic Inspection 4A-13. . . . . . . . . . . . . . . . . . Motor 4A-13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Removal 4A-13. . . . . . . . . . . . . . . . . . . . . . . . Disassembly 4A-13. . . . . . . . . . . . . . . . . . . . . Cleaning and Inspection 4A-16. . . . . . . . . . . Reassembly 4A-17. . . . . . . . . . . . . . . . . . . . . Checking Pinion Clearance 4A-21. . . . . . . . Installation 4A-22. . . . . . . . . . . . . . . . . . . . . . .

Delco PG260 Starter 4A-23. . . . . . . . . . . . . . . . . PG260 Specifications 4A-23. . . . . . . . . . . . . Torque Specification 4A-23. . . . . . . . . . . . . . Lubricants / Sealants 4A-23. . . . . . . . . . . . . . Description 4A-23. . . . . . . . . . . . . . . . . . . . . .

PG260 Exploded View 4A-24. . . . . . . . . . . . . . . Solenoid Switch 4A-25. . . . . . . . . . . . . . . . . . . . . Periodic Inspection 4A-25. . . . . . . . . . . . . . . . . . Motor 4A-26. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Removal 4A-26. . . . . . . . . . . . . . . . . . . . . . . . Disassembly 4A-26. . . . . . . . . . . . . . . . . . . . . Cleaning and Inspection 4A-30. . . . . . . . . . . Armature Tests 4A-31. . . . . . . . . . . . . . . . . . . Armature Bearing (Commutator End) 4A-32Gear Bearing 4A-32. . . . . . . . . . . . . . . . . . . . Shaft Assembly Bearing 4A-33. . . . . . . . . . . Drive End Housing Bearing 4A-33. . . . . . . . Brushes and Brush Holder 4A-34. . . . . . . . .

Section 4B - Thunderbolt V Ignition SystemReplacement Parts Warning 4B-2. . . . . . . . . . General Precautions 4B-2. . . . . . . . . . . . . . . . . EFI System Maintenance Precautions 4B-3. Thunderbolt V Ignition System 4B-4. . . . . . . .

Identification 4B-4. . . . . . . . . . . . . . . . . . . . . Timing and Idle Adjustment Procedures 4B-5

Setting Base Ignition Timing 4B-5. . . . . . . . Adjusting Idle Mixture 4B-5. . . . . . . . . . . . .

Spark Plugs 4B-6. . . . . . . . . . . . . . . . . . . . . . . . Specifications 4B-6. . . . . . . . . . . . . . . . . . . . Removal 4B-6. . . . . . . . . . . . . . . . . . . . . . . . Inspection 4B-6. . . . . . . . . . . . . . . . . . . . . . . Replacing 4B-7. . . . . . . . . . . . . . . . . . . . . . .

Description 4B-7. . . . . . . . . . . . . . . . . . . . . . . . . Idle Speed Spark Control 4B-7. . . . . . . . . . Acceleration Spark Advance 4B-8. . . . . . . Mean-Best-Timing (MBT) Spark Advance 4B-8. . . . . . . . . . . . . . . . . . Over-Speed Control 4B-8. . . . . . . . . . . . . . . Knock Retard Spark Control 4B-8. . . . . . .

Spark Plug Wires 4B-9. . . . . . . . . . . . . . . . . . . . Adjusting Engine Idle Speed 4B-9. . . . . . .

Circuit Description 4B-10. . . . . . . . . . . . . . . . . . . Ignition Control Module 4B-10. . . . . . . . . . . . Knock Control Module 4B-10. . . . . . . . . . . . . Ignition Control System Timing Lead 4B-10

Thunderbolt V Spark Control Graph 4B-11. . . Distributor Advance Curves 4B-12. . . . . . . . . . . Distributor 4B-12. . . . . . . . . . . . . . . . . . . . . . . . . .

Removal 4B-12. . . . . . . . . . . . . . . . . . . . . . . . Disassembly 4B-13. . . . . . . . . . . . . . . . . . . . . Reassembly 4B-13. . . . . . . . . . . . . . . . . . . . . Installation - Engine Not Disturbed 4B-14. . Installation - Engine Disturbed 4B-14. . . . . .

Distributor Cap 4B-15. . . . . . . . . . . . . . . . . . . . . . Removal 4B-15. . . . . . . . . . . . . . . . . . . . . . . . Inspection 4B-15. . . . . . . . . . . . . . . . . . . . . . .

Rotor/Sensor Wheel 4B-16. . . . . . . . . . . . . . . . . Removal 4B-16. . . . . . . . . . . . . . . . . . . . . . . . Inspection 4B-16. . . . . . . . . . . . . . . . . . . . . . . Installation 4B-17. . . . . . . . . . . . . . . . . . . . . . .

Sensor 4B-17. . . . . . . . . . . . . . . . . . . . . . . . . . . . . Removal 4B-17. . . . . . . . . . . . . . . . . . . . . . . . Inspection 4B-18. . . . . . . . . . . . . . . . . . . . . . . Installation 4B-18. . . . . . . . . . . . . . . . . . . . . . .

Page viii 90-861328--1 NOVEMBER 1999

Section 4C - Charging SystemGeneral Precautions 4C-2. . . . . . . . . . . . . . . . . EFI Electrical System Precautions 4C-2. . . . . Replacement Parts Warning 4C-2. . . . . . . . . . Multiple EFI Engine Battery Precautions 4C-3

Situation 4C-3. . . . . . . . . . . . . . . . . . . . . . . . . Recommendations 4C-3. . . . . . . . . . . . . . . .

Identification 4C-4. . . . . . . . . . . . . . . . . . . . . . . . Specifications 4C-4. . . . . . . . . . . . . . . . . . . . . . .

Mando 4C-4. . . . . . . . . . . . . . . . . . . . . . . . . . DelcoRemy 4C-5. . . . . . . . . . . . . . . . . . . . . .

Tools 4C-5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Lubricants / Sealants / Adhesives 4C-5. . . . . Torque Specifications 4C-5. . . . . . . . . . . . . . . . Description 4C-6. . . . . . . . . . . . . . . . . . . . . . . . .

Testing 4C-7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . Charging System 4C-7. . . . . . . . . . . . . . . . . Charging System Resistance 4C-8. . . . . . . Circuitry 4C-10. . . . . . . . . . . . . . . . . . . . . . . . . Component 4C-11. . . . . . . . . . . . . . . . . . . . . .

Exploded View 4C-16. . . . . . . . . . . . . . . . . . . . . . Alternator Repair 4C-17. . . . . . . . . . . . . . . . . . . .

Removal 4C-17. . . . . . . . . . . . . . . . . . . . . . . . Disassembly 4C-17. . . . . . . . . . . . . . . . . . . . . Cleaning and Inspection 4C-22. . . . . . . . . . . Reassembly 4C-22. . . . . . . . . . . . . . . . . . . . .

Installation 4C-26. . . . . . . . . . . . . . . . . . . . . . . . . Pulley Removal 4C-27. . . . . . . . . . . . . . . . . . Battery Isolator Diagram 4C-28. . . . . . . . . . .

Section 4D - InstrumentationTools 4D-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Lubricants / Sealants / Adhesives 4D-2. . . . . Identification 4D-2. . . . . . . . . . . . . . . . . . . . . . . . Special Information 4D-3. . . . . . . . . . . . . . . . . .

Lighting Options 4D-3. . . . . . . . . . . . . . . . . . Gauges 4D-5. . . . . . . . . . . . . . . . . . . . . . . . . . . .

Oil, Fuel and Temperature 4D-5. . . . . . . . . Battery Gauge 4D-6. . . . . . . . . . . . . . . . . . . Cruiselog Meter 4D-7. . . . . . . . . . . . . . . . . . Vacuum Gauge 4D-7. . . . . . . . . . . . . . . . . . . Speedometer 4D-7. . . . . . . . . . . . . . . . . . . . Tachometer 4D-8. . . . . . . . . . . . . . . . . . . . . . Gauge Replacement 4D-8. . . . . . . . . . . . . .

Senders 4D-9. . . . . . . . . . . . . . . . . . . . . . . . . . . . Oil Pressure 4D-9. . . . . . . . . . . . . . . . . . . . . Water Temperature 4D-10. . . . . . . . . . . . . . . Fuel Tank Sender 4D-13. . . . . . . . . . . . . . . . .

Switches 4D-16. . . . . . . . . . . . . . . . . . . . . . . . . . . Ignition Key Switch 4D-16. . . . . . . . . . . . . . . Lanyard Stop Switches 4D-17. . . . . . . . . . . . Testing 4D-17. . . . . . . . . . . . . . . . . . . . . . . . . . Start/Stop Switch 4D-19. . . . . . . . . . . . . . . . .

Audio Warning System 4D-20. . . . . . . . . . . . . . . Buzzer 4D-20. . . . . . . . . . . . . . . . . . . . . . . . . . Oil Pressure Switch 4D-21. . . . . . . . . . . . . . . Water Temperature Switch 4D-21. . . . . . . . .

Section 4E - Wiring DiagramsWiring Colors for Mercury MerCruiser 4E-2. . MCM Gasoline Engine Wiring Diagrams 4E-4

Starting and Charging Harness 4E-4. . . . . Fuel and Ignition System Harnesses 4E-16Quicksilver Instrumentation 4E-22. . . . . . . . Dual Station Wiring 4E-24. . . . . . . . . . . . . . .

FUEL SYSTEMSection 5A - Fuel Delivery System For Carbureted Engines

Identification 5A-2. . . . . . . . . . . . . . . . . . . . . . . . Replacement Parts Warning 5A-2. . . . . . . . . . Specifications 5A-2. . . . . . . . . . . . . . . . . . . . . . . Torque Specifications 5A-2. . . . . . . . . . . . . . . . Tools 5A-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Lubricants / Sealants / Adhesives 5A-3. . . . . Precautions 5A-3. . . . . . . . . . . . . . . . . . . . . . . .

Fuel Supply Connections 5A-3. . . . . . . . . .

Fuel Delivery System 5A-4. . . . . . . . . . . . . . . . Recommendations 5A-4. . . . . . . . . . . . . . . .

Fuel System Components 5A-6. . . . . . . . . . . . Water Separating Fuel Filter 5A-7. . . . . . . . . .

Replacement 5A-8. . . . . . . . . . . . . . . . . . . . . Vent Hose Routing 5A-8. . . . . . . . . . . . . . . . . .

Carbureted Models 5A-8. . . . . . . . . . . . . . .

90-861328--1 NOVEMBER 1999 Page ix

Section 5B - Mercarb 2 Barrel Carburetor

Identification 5B-2. . . . . . . . . . . . . . . . . . . . . . . . Replacement Parts Warning 5B-3. . . . . . . . . . Precautions 5B-3. . . . . . . . . . . . . . . . . . . . . . . . Torque Specifications 5B-3. . . . . . . . . . . . . . . . Specifications 5B-4. . . . . . . . . . . . . . . . . . . . . . . Tools 5B-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Exploded View 5B-6. . . . . . . . . . . . . . . . . . . . . . Important Service Information 5B-8. . . . . . . . .

High Altitude Re-Jetting 5B-8. . . . . . . . . . . 8 Point Carburetor Check List 5B-9. . . . . . Flooding At Idle RPM 5B-9. . . . . . . . . . . . . Needle / Seat Change 5B-9. . . . . . . . . . . . . Adjustable Accelerator Pump Lever 5B-10.

Description 5B-10. . . . . . . . . . . . . . . . . . . . . . . . .

Maintenance 5B-11. . . . . . . . . . . . . . . . . . . . . . . . Flame Arrestor 5B-11. . . . . . . . . . . . . . . . . . . Fuel Inlet Filter 5B-13. . . . . . . . . . . . . . . . . . . Choke Inspection 5B-14. . . . . . . . . . . . . . . . .

Adjustments 5B-14. . . . . . . . . . . . . . . . . . . . . . . . Accelerator Rod 5B-14. . . . . . . . . . . . . . . . . . Choke Setting 5B-16. . . . . . . . . . . . . . . . . . . . Choke Unloader 5B-17. . . . . . . . . . . . . . . . . . Initial Idle Speed and Mixture 5B-17. . . . . . . Final Idle Speed and Mixture 5B-18. . . . . . .

Replacing Carburetor 5B-18. . . . . . . . . . . . . . . . Repair 5B-19. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Removal 5B-19. . . . . . . . . . . . . . . . . . . . . . . . Disassembly 5B-20. . . . . . . . . . . . . . . . . . . . . Cleaning and Inspection 5B-28. . . . . . . . . . . Reassembly 5B-30. . . . . . . . . . . . . . . . . . . . . Installation 5B-40. . . . . . . . . . . . . . . . . . . . . . .

Section 5C - Weber 4 Barrel CarburetorIdentification 5C-2. . . . . . . . . . . . . . . . . . . . . . . .

Carburetor Metering Rod And Jet Identification 5C-2. . . . . . . . . . . . .

Torque Specifications 5C-4. . . . . . . . . . . . . . . . Specifications 5C-4. . . . . . . . . . . . . . . . . . . . . . . Tools 5C-5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Replacement Parts Warning 5C-5. . . . . . . . . . Precautions 5C-6. . . . . . . . . . . . . . . . . . . . . . . . Fuel Delivery System 5C-6. . . . . . . . . . . . . . . .

Fuel Supply Connections 5C-6. . . . . . . . . . 8 Point Carburetor Check List 5C-7. . . . . . . . . Exploded View 5C-8. . . . . . . . . . . . . . . . . . . . . . Description 5C-10. . . . . . . . . . . . . . . . . . . . . . . . . Important Service Information 5C-11. . . . . . . . .

Adjustable Accelerator Pump Lever 5C-11. Hard Starting 5C-11. . . . . . . . . . . . . . . . . . . . .

Maintenance 5C-12. . . . . . . . . . . . . . . . . . . . . . . . Flame Arrestor 5C-12. . . . . . . . . . . . . . . . . . . Fuel Inlet Filter 5C-13. . . . . . . . . . . . . . . . . . .

Adjustments 5C-14. . . . . . . . . . . . . . . . . . . . . . . . Accelerator Pump 5C-14. . . . . . . . . . . . . . . . Float Drop 5C-16. . . . . . . . . . . . . . . . . . . . . . . Float Level 5C-17. . . . . . . . . . . . . . . . . . . . . . . Electric Choke 5C-18. . . . . . . . . . . . . . . . . . . Idle Speed and Mixture 5C-18. . . . . . . . . . . .

Replacing Carburetor 5C-19. . . . . . . . . . . . . . . . Repair 5C-19. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Removal 5C-19. . . . . . . . . . . . . . . . . . . . . . . . Disassembly 5C-21. . . . . . . . . . . . . . . . . . . . . . . . Cleaning and Inspection 5C-32. . . . . . . . . . . . . . Reassembly 5C-33. . . . . . . . . . . . . . . . . . . . . . . .

Installation 5C-44. . . . . . . . . . . . . . . . . . . . . . .

Section 5D - Sav1 Emission Fuel System With Weber 4 BarrelCarburetor

Identification 5D-2. . . . . . . . . . . . . . . . . . . . . . . . Replacement Parts Warning 5D-2. . . . . . . . . . Torque Specifications 5D-2. . . . . . . . . . . . . . . . Special Tools 5D-2. . . . . . . . . . . . . . . . . . . . . . . Engine Specifications 5D-3. . . . . . . . . . . . . . . . Carburetor Specifications 5D-3. . . . . . . . . . . . . Carburetor Adjustment Specifications 5D-4. . Description 5D-4. . . . . . . . . . . . . . . . . . . . . . . . . Special Notes 5D-5. . . . . . . . . . . . . . . . . . . . . . .

Carburetor Top Cover 5D-5. . . . . . . . . . . . . Sealed Idle Mixture Screws 5D-5. . . . . . . . Piston Bore of Emissions Model 5D-6. . . .

Precautions 5D-6. . . . . . . . . . . . . . . . . . . . . . . . Maintenance 5D-7. . . . . . . . . . . . . . . . . . . . . . . .

Flame Arrestor 5D-7. . . . . . . . . . . . . . . . . . . Fuel Filter 5D-7. . . . . . . . . . . . . . . . . . . . . . . Positive Crankcase Ventilation (PCV) 5D-8

Troubleshooting 5D-8. . . . . . . . . . . . . . . . . . . . . Checking Ported Vacuum Switch andCarburetor Vacuum Circuit for Correct Operation 5D-9. . . . . . . . . . . . .

Service Procedures 5D-11. . . . . . . . . . . . . . . . . . Checking Positive Crankcase Ventilation (PCV) Valve 5D-11. . . . . . . . . . . Removing Seals From Idle Mixture Screws 5D-11. . . . . . . . . . . . . . Installing New Seals 5D-12. . . . . . . . . . . . . . Carburetor Installation 5D-12. . . . . . . . . . . . . Ported Vacuum Switch Installation 5D-13. . Emissions System Connections 5D-13. . . . Propane Assisted Idle Set Procedure 5D-15

Test Equipment 5D-18. . . . . . . . . . . . . . . . . . . . . Emissions Testing 5D-19. . . . . . . . . . . . . . . . . . .

Page x 90-861328--1 NOVEMBER 1999

Section 5E - Fuel Delivery SystemFor Electronic Fuel Injection

Specifications 5E-2. . . . . . . . . . . . . . . . . . . . . . . Torque Specifications 5E-2. . . . . . . . . . . . . . . . Tools 5E-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Lubricants / Sealants / Adhesives 5E-2. . . . . Replacement Parts Warning 5E-2. . . . . . . . . . Precautions 5E-3. . . . . . . . . . . . . . . . . . . . . . . . Fuel Supply Connections 5E-3. . . . . . . . . . . . . Fuel Delivery System 5E-4. . . . . . . . . . . . . . . .

Recommendations 5E-4. . . . . . . . . . . . . . . . Cool Fuel System Exploded View 5E-5. . . . . Fuel System Flow Diagrams 5E-6. . . . . . . . . .

Throttle Body Injection 5E-6. . . . . . . . . . . .

Water Separating Fuel Filter 5E-7. . . . . . . . . . Water Separating Fuel Filter Replacement 5E-8. . . . . . . . . . . . . . . . . . . .

Cool Fuel System Repair 5E-8. . . . . . . . . . . . . Removal 5E-8. . . . . . . . . . . . . . . . . . . . . . . . Disassembly 5E-10. . . . . . . . . . . . . . . . . . . . . Reassembly 5E-11. . . . . . . . . . . . . . . . . . . . . Installation 5E-13. . . . . . . . . . . . . . . . . . . . . . .

Vacuum and Vent Hose Routing 5E-15. . . . . . . Throttle Body EFI 5E-15. . . . . . . . . . . . . . . . .

Section 5F - Fuel Injection Descriptions AndSystem Operation

Special Tools 5F-2. . . . . . . . . . . . . . . . . . . . . . . Service Precautions 5F-3. . . . . . . . . . . . . . . . . General Information 5F-5. . . . . . . . . . . . . . . . .

Introduction 5F-5. . . . . . . . . . . . . . . . . . . . . . Visual/Physical Inspection 5F-5. . . . . . . . . Basic Knowledge and Tools Required 5F-5Electrostatic Discharge Damage 5F-5. . . . Diagnostic Information 5F-5. . . . . . . . . . . . Wiring Harness Service 5F-6. . . . . . . . . . . Wiring Connector Service 5F-7. . . . . . . . . .

Abbreviations 5F-8. . . . . . . . . . . . . . . . . . . . . . . ECM Self-Diagnostics 5F-9. . . . . . . . . . . . . . . .

Diagnostic Code Tool With Malfunction Indicator Lamp 5F-9. . . Intermittent Malfunction Indicator Lamp 5F-9. . . . . . . . . . . . . . . . . . . Reading Codes 5F-10. . . . . . . . . . . . . . . . . . . Scan Tools 5F-11. . . . . . . . . . . . . . . . . . . . . . . EFI Diagnostic Circuit Check 5F-11. . . . . . . Scan Tool Use With Intermittents 5F-11. . . Non-Scan Diagnosis of Driveability Concerns (With No Codes Set) 5F-12. . . .

Electronic Control Module (ECM) and Sensors 5F-13. . . . . . . . . . . . . . . . . . . . . . .

General Description 5F-13. . . . . . . . . . . . . . . Computers and Voltage Signals 5F-13. . . . Analog Signals 5F-13. . . . . . . . . . . . . . . . . . . Digital Signals 5F-14. . . . . . . . . . . . . . . . . . . . Engine Control Module (ECM) 5F-15. . . . . . Speed Density System 5F-16. . . . . . . . . . . . ECM Input and Sensor Descriptions 5F-17.

Spark Management 5F-22. . . . . . . . . . . . . . . . . . High Energy Ignition with Ignition Control (IC) 5F-22. . . . . . . . . . . . . . Modes Of Operation 5F-23. . . . . . . . . . . . . . Base Ignition Timing 5F-24. . . . . . . . . . . . . . Results of Incorrect Operation 5F-25. . . . . .

Fuel Metering System 5F-26. . . . . . . . . . . . . . . . General Description 5F-26. . . . . . . . . . . . . . . Cool Fuel Systems 5F-26. . . . . . . . . . . . . . . . Modes of Operation 5F-26. . . . . . . . . . . . . . . Throttle Body Injection Components 5F-28.

Section 5G - Fuel Injection Disassembly And ReassemblyPrecautions 5G-2. . . . . . . . . . . . . . . . . . . . . . . . Torque Specifications 5G-3. . . . . . . . . . . . . . . . Flame Arrestor And Throttle Body 5G-4. . . . . Exploded Views - Throttle Body EFI 5G-7. . .

Throttle Body Body And Adapter 5G-7. . . . Throttle Body Assembly 5G-8. . . . . . . . . . .

Fuel Pressure Relief Procedure 5G-9. . . . . . . Throttle Body EFI Components 5G-9. . . . . . .

Fuel Meter Cover Assembly 5G-9. . . . . . . . Fuel Injectors 5G-11. . . . . . . . . . . . . . . . . . . . Throttle Body 5G-13. . . . . . . . . . . . . . . . . . . .

Throttle Body Adapter Plate 5G-17. . . . . . . . Engine Control Module (ECM) 5G-18. . . . . . Knock Sensor (KS) Module (MEFI 1 Only) 5G-19. . . . . . . . . . . . . . . . . . . Engine Coolant Temperature (ECT) Sensor 5G-20. . . . . . . . . . . . . . . . . . . . Manifold Absolute Pressure (MAP) Sensor 5G-21. . . . . . . . . . . . . . . . . . . Throttle Position (TP) Sensor 5G-22. . . . . . . Idle Air Control (IAC) Valve 5G-23. . . . . . . . Knock Sensor 5G-25. . . . . . . . . . . . . . . . . . . .

90-861328--1 NOVEMBER 1999 Page xi

Section 5H - Fuel Injection System TroubleshootingScan Tool Normal Specifications 5H-2. . . . . . Important Preliminary Checks 5H-3. . . . . . . . .

Before Starting 5H-3. . . . . . . . . . . . . . . . . . . Visual / Physical Check 5H-3. . . . . . . . . . . .

Intermittents 5H-4. . . . . . . . . . . . . . . . . . . . . . . . Hard Start Symptom 5H-5. . . . . . . . . . . . . . . . . Surges and/or Chuggles Symptom 5H-7. . . . Lack of Power, Sluggish or Spongy Symptom 5H-9. . . . . . . . . . . . . . . .

Detonation / Spark Knock Symptom 5H-11. . . Hesitation, Sag, Stumble Symptom 5H-13. . . . Cuts Out, Misses Symptom 5H-15. . . . . . . . . . . Rough, Unstable or Incorrect Idle, Stalling Symptom 5H-17. . . . . . . . . . . . . . . . . . . Poor Fuel Economy Symptom 5H-20. . . . . . . . Dieseling, Run-On Symptom 5H-22. . . . . . . . . . Backfire Symptom 5H-23. . . . . . . . . . . . . . . . . . .

Section 5I - DiagnosticsSpecial Tools 5I-2. . . . . . . . . . . . . . . . . . . . . . . Diagnostic Circuit Check 5I-4. . . . . . . . . . . . .

Scan Tool Normal Specifications 5I-4. . . . Diagnostic Trouble Codes 5I-5. . . . . . . . . . . . ECM Connector and EFI Symptoms Chart 5I-6. . . . . . . . . . . . . . . .

J-1 Circuits with MEFI 1 5I-6. . . . . . . . . . . J-2 Circuits with MEFI 1 5I-8. . . . . . . . . . . J-1 Circuits with MEFI 3 5I-10. . . . . . . . . . . J-2 Circuits with MEFI 3 5I-12. . . . . . . . . . .

Wiring System Diagrams 5I-14. . . . . . . . . . . . . MEFI 1 5I-14. . . . . . . . . . . . . . . . . . . . . . . . . . MEFI 3 5I-18. . . . . . . . . . . . . . . . . . . . . . . . . .

General Diagnostic Tests 5I-21. . . . . . . . . . . . . On-Board Diagnostic (OBD) System Check 5I-21. . . . . . . . . . . . . Chart A-1 No MIL or No DLC Data 5I-23. Chart A-2 MIL ON Steady - Will Not Flash DTC 12 5I-25. . . . . . . . . . . . Chart A-3 Engine Cranks But Will Not Run 5I-27. . . . . . . . . . . . . . . . . . . . . Chart A-4 Fuel System Diagnosis 5I-29. . Chart A-5 Fuel System Electrical Test 5I-31Chart A-6 EFI System / Ignition Relay Check 5I-33. . . . . . . . . . . . . Chart A-7 Ignition System Check 5I-35. . . Chart A-8 Idle Air Control (IAC) Functional Test 5I-41. . . . . . . . . . . . . Discrete Input Circuit Check - Non-Scan Only 5I-43. . . . . . . . . . . . . . . . . .

Clearing Trouble Codes 5I-48. . . . . . . . . . . . . . Clearing Codes Using CodeMate Tester 5I-48. . . . . . . . . . . . . . . . . Clearing Codes Using Scan Tool 5I-48. . . .

Diagnostic Testing 5I-49. . . . . . . . . . . . . . . . . . . Code 14 Engine Coolant Temperature (ECT) Sensor Circuit 5I-49. . . . . . . . . . . . . Code 15 Engine Coolant Temperature (ECT) Sensor Circuit 5I-52. . . . . . . . . . . . . Code 21 Throttle Position (TP) Sensor Circuit 5I-54. . . . . . . . . . . . . . . Code 22 Throttle Position (TP) Sensor Circuit 5I-57. . . . . . . . . . . . . . . Code 23 Intake Air Temperature (IAT) Sensor Circuit 5I-60. . . . . . . . . . . . . . Code 25 Intake Air Temperature (IAT) Sensor Circuit 5I-62. . . . . . . . . . . . . . Code 33 Manifold Absolute Pressure (MAP) Sensor Circuit 5I-64. . . . . . . . . . . . . Code 34 Manifold Absolute Pressure (MAP) Sensor Circuit 5I-67. . . . . . . . . . . . . Code 41 Ignition Control (IC) Circuit 5I-70Code 42 Ignition Control (IC) Circuit 5I-72Code 43 Knock Sensor (KS) Circuit 5I-74Code 44 Knock Sensor (KS) Circuit 5I-77Code 45 Ignition Coil Driver Fault 5I-80. . Code 51 Calibration Memory Failure 5I-82Code 52 EEPROM Failure 5I-83. . . . . . . . Code 61 Fuel Pressure (FP) Circuit 5I-84. Code 62 Fuel Pressure (FP) Sensor Circuit 5I-87. . . . . . . . . . . . . . .

Page xii 90-861328--1 NOVEMBER 1999

COOLING SYSTEMSection 6A - Seawater Cooled Models

Torque Specifications 6A-2. . . . . . . . . . . . . . . . Tools 6A-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Special Tools 6A-2. . . . . . . . . . . . . . . . . . . . . Lubricants / Sealants / Adhesives 6A-3. . . . . Specifications 6A-3. . . . . . . . . . . . . . . . . . . . . . . Seawater Inlet Recommendations 6A-4. . . . .

Transom Mounted or Through The Hull Seawater Pickups and Hose 6A-4. . . . . . . Seacock (Seawater Inlet Valve) 6A-4. . . . . Sea Strainer 6A-4. . . . . . . . . . . . . . . . . . . . .

Seawater Pickups 6A-5. . . . . . . . . . . . . . . . . . . Through The Hull Mounted 6A-5. . . . . . . . . Transom Mounted 6A-6. . . . . . . . . . . . . . . .

Quicksilver Sea Strainer 6A-7. . . . . . . . . . . . . . Removal 6A-7. . . . . . . . . . . . . . . . . . . . . . . . Cleaning and Inspection 6A-9. . . . . . . . . . . Installation 6A-9. . . . . . . . . . . . . . . . . . . . . . .

Seawater Pickup Pump 6A-11. . . . . . . . . . . . . . Output Test 6A-11. . . . . . . . . . . . . . . . . . . . . . Disassembly 6A-13. . . . . . . . . . . . . . . . . . . . . Reassembly 6A-14. . . . . . . . . . . . . . . . . . . . .

Seawater Pump Bearing Housing 6A-15. . . . . Disassembly 6A-15. . . . . . . . . . . . . . . . . . . . . Cleaning and Inspection 6A-16. . . . . . . . . . . Reassembly 6A-17. . . . . . . . . . . . . . . . . . . . .

Water Circulating Pump 6A-20. . . . . . . . . . . . . . Removal 6A-20. . . . . . . . . . . . . . . . . . . . . . . . Cleaning and Inspection 6A-20. . . . . . . . . . . Installation 6A-20. . . . . . . . . . . . . . . . . . . . . . .

Drive Belt Tension Adjustment 6A-21. . . . . . . . Flushing Seawater Cooling System 6A-21. . . . Thermostat 6A-21. . . . . . . . . . . . . . . . . . . . . . . . .

Removal 6A-21. . . . . . . . . . . . . . . . . . . . . . . . Testing 6A-22. . . . . . . . . . . . . . . . . . . . . . . . . . Installation 6A-23. . . . . . . . . . . . . . . . . . . . . . .

Auxiliary Hot Water Heater Installation Information 6A-24. . . . . . . . . . . . . . Seawater Flow Diagrams 6A-28. . . . . . . . . . . . .

MCM 262 cid / 4.3L Alpha 6A-28. . . . . . . . . MCM 262 cid / 4.3L Bravo 6A-29. . . . . . . . .

Draining Diagrams 6A-30. . . . . . . . . . . . . . . . . . MCM 262 cid / 4.3L Alpha 6A-30. . . . . . . . . MCM 262 cid / 4.3L Bravo 6A-31. . . . . . . . .

Section 6B - Closed Cooled ModelsTorque Specifications 6B-2. . . . . . . . . . . . . . . . Lubricants / Sealants / Adhesives 6B-2. . . . . Specifications 6B-2. . . . . . . . . . . . . . . . . . . . . . .

Closed Cooling System Capacity 6B-2. . . Coolant Specification 6B-2. . . . . . . . . . . . . . Thermostat 6B-2. . . . . . . . . . . . . . . . . . . . . . Pressure Cap Rating 6B-2. . . . . . . . . . . . . .

Description 6B-3. . . . . . . . . . . . . . . . . . . . . . . . . Coolant Recommendations 6B-3. . . . . . . . . . . Maintaining Coolant Level 6B-3. . . . . . . . . . . . Pressure Cap Maintenance 6B-4. . . . . . . . . . . Heat Exchanger Repair 6B-5. . . . . . . . . . . . . . Testing Closed Cooling System 6B-6. . . . . . .

Testing Coolant for Alkalinity 6B-6. . . . . . . Pressure Testing System 6B-6. . . . . . . . . . Testing for Cylinder Head Gasket Leak 6B-7. . . . . . . . . . . . . . . . . . . . . Testing Heat Exchanger 6B-8. . . . . . . . . . . Testing Pressure Cap 6B-8. . . . . . . . . . . . .

Thermostat 6B-10. . . . . . . . . . . . . . . . . . . . . . . . . Removal 6B-10. . . . . . . . . . . . . . . . . . . . . . . . Testing 6B-11. . . . . . . . . . . . . . . . . . . . . . . . . . Installation 6B-12. . . . . . . . . . . . . . . . . . . . . . .

Changing Coolant 6B-13. . . . . . . . . . . . . . . . . . . Closed Cooling Section 6B-13. . . . . . . . . . . . Change Intervals 6B-13. . . . . . . . . . . . . . . . . Draining Instructions 6B-13. . . . . . . . . . . . . .

Cleaning System 6B-14. . . . . . . . . . . . . . . . . . . . Closed Cooling Section 6B-14. . . . . . . . . . . . Seawater Section 6B-15. . . . . . . . . . . . . . . . .

Filling Closed Cooling Section 6B-16. . . . . . . . Auxiliary Hot Water Heater Installation 6B-18. Heat Exchanger Bracket Hardware 6B-19. . . . Heat Exchanger Hose Connections 6B-20. . . . Water Flow Diagram 6B-21. . . . . . . . . . . . . . . . .

MCM 262 cid / 4.3L Alpha 6B-21. . . . . . . . . MCM 262 cid / 4.3L Bravo 6B-22. . . . . . . . .

90-861328--1 NOVEMBER 1999 Page xiii

EXHAUST SYSTEMSection 7A - General

Exhaust System Requirements 7A-2. . . . . . . . Exhaust Elbow Risers 7A-2. . . . . . . . . . . . . MCM (Sterndrive) Engines With Through The Transom Exhaust 7A-2

Section 7B - Manifolds, Elbows and RisersTorque Specifications 7B-2. . . . . . . . . . . . . . . . Lubricants / Sealants / Adhesives 7B-2. . . . . Exhaust Riser (Kit) 7B-2. . . . . . . . . . . . . . . . . . Disassembly 7B-2. . . . . . . . . . . . . . . . . . . . . . . . Cleaning and Inspection 7B-4. . . . . . . . . . . . . .

Installation 7B-6. . . . . . . . . . . . . . . . . . . . . . . . . Gaskets 7B-6. . . . . . . . . . . . . . . . . . . . . . . . . Manifold 7B-7. . . . . . . . . . . . . . . . . . . . . . . . . Sterndrive Exhaust Extension 7B-9. . . . . .

Section 7C - CollectorsTorque Specifications 7C-2. . . . . . . . . . . . . . . . Lubricants / Sealants / Adhesives 7C-2. . . . . Bullhorn Exhaust 7C-3. . . . . . . . . . . . . . . . . . . .

Shutter Replacement 7C-3. . . . . . . . . . . . . . Component Replacement 7C-4. . . . . . . . . .

DRIVESSection 8A - Drive Shaft

Torque Specifications 8A-2. . . . . . . . . . . . . . . . Tools 8A-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Lubricants / Sealants / Adhesives 8A-2. . . . . Flywheel Housing / Output Shaft Housing Repair 8A-3. . . . . . . . . . . . . . . . . . . . .

Exploded View 8A-3. . . . . . . . . . . . . . . . . . . Removal and Installation 8A-4. . . . . . . . . . Disassembly 8A-4. . . . . . . . . . . . . . . . . . . . . Reassembly 8A-5. . . . . . . . . . . . . . . . . . . . .

Drive Shaft Repair 8A-5. . . . . . . . . . . . . . . . . . . Removal 8A-5. . . . . . . . . . . . . . . . . . . . . . . . Repair 8A-7. . . . . . . . . . . . . . . . . . . . . . . . . .

Replacement Drive Shafts 8A-7. . . . . . . . . Drive Shafts Modified to Shorter Lengths 8A-8. . . . . . . . . . . . . . . . . .

Installation 8A-8. . . . . . . . . . . . . . . . . . . . . . . . . Bearing Support Repair 8A-10. . . . . . . . . . . . . .

Removal 8A-10. . . . . . . . . . . . . . . . . . . . . . . . Disassembly 8A-10. . . . . . . . . . . . . . . . . . . . . Reassembly 8A-11. . . . . . . . . . . . . . . . . . . . . Installation 8A-12. . . . . . . . . . . . . . . . . . . . . . .

Page xiv 90-861328--1 NOVEMBER 1999

POWER STEERING SYSTEMSection 9A - Pump And Related Components

Torque Specifications 9A-2. . . . . . . . . . . . . . . . Tools 9A-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Special Tools 9A-2. . . . . . . . . . . . . . . . . . . . Lubricants / Sealants / Adhesives 9A-2. . . . . Precautions 9A-3. . . . . . . . . . . . . . . . . . . . . . . . Power Steering Pump and Components(Exploded View) 9A-3. . . . . . . . . . . . . . . . . . . . Serpentine Belt Routing 9A-4. . . . . . . . . . . . . .

S/N 0L619083 and Below 9A-4. . . . . . . . . . S/N 0L619084 and Above 9A-5. . . . . . . . .

Serpentine Belt Adjustment 9A-6. . . . . . . . . . . Removal 9A-6. . . . . . . . . . . . . . . . . . . . . . . . Installation 9A-6. . . . . . . . . . . . . . . . . . . . . . .

Important Service Information 9A-7. . . . . . . . . Pump Pulley Replacement 9A-7. . . . . . . . .

Testing and Repair 9A-8. . . . . . . . . . . . . . . . . . Checking Pump Fluid Level 9A-8. . . . . . . . . . . Filling and Air Bleeding System 9A-8. . . . . . . Pump Assembly 9A-8. . . . . . . . . . . . . . . . . . . . .


Hydraulic Hoses and Fluid Cooler 9A-11. . . . . High Pressure Hose (Pump-to-Control Valve) 9A-11. . . . . . . . . . Low Pressure Hose (Cooler-to-Pump) 9A-13. . . . . . . . . . . . . . . . Low Pressure Hose (Control Valve-to-Cooler) 9A-15. . . . . . . . . .

1A

GENERAL INFORMATIONSERVICE MANUAL NUMBER 25

90-861328--1 NOVEMBER 1999 Page 1A-1

IMPORTANT INFORMATIONSection 1A - General Information

Table of Contents

Introduction 1A-2. . . . . . . . . . . . . . . . . . . . . . . . . How to Use This Manual 1A-2. . . . . . . . . . . . .

Page Numbering 1A-2. . . . . . . . . . . . . . . . . How to Read a Parts Manual 1A-3. . . . . . . . . Directional References 1A-4. . . . . . . . . . . . . . . Engine Rotation 1A-4. . . . . . . . . . . . . . . . . . . . . Engine Serial Number Location 1A-5. . . . . . .

Propeller Information 1A-5. . . . . . . . . . . . . . . . Water Testing New Engines 1A-6. . . . . . . . . . Boat and Engine Performance 1A-6. . . . . . . .

Boat Bottom 1A-6. . . . . . . . . . . . . . . . . . . . . Marine Fouling 1A-7. . . . . . . . . . . . . . . . . . . Weight Distribution 1A-8. . . . . . . . . . . . . . . . Water in Boat 1A-9. . . . . . . . . . . . . . . . . . . . Elevation and Climate 1A-9. . . . . . . . . . . . .

GENERAL INFORMATION SERVICE MANUAL NUMBER 25

Page 1A-2 90-861328--1 NOVEMBER 1999

Introduction

This comprehensive overhaul and repair manual is designed as a service guide for themodels previously listed. It provides specific information, including procedures fordisassembly, inspection, assembly and adjustment to enable dealers and servicemechanics to repair and tune these engines.

Before attempting repairs or tune-up, it is suggested that the procedure first be read throughto gain knowledge of the methods and tools used and the cautions and warnings requiredfor safety.

How to Use This Manual

This manual is divided into sections which represent major components and systems.

Some sections are further divided into parts which more fully describe the component.

Sections and section parts are listed on the “Service Manual Outline” page following “V-6Models Covered in This Manual” page.

Page NumberingTwo number groups appear at the bottom of each page. Following is an example anddescription.

a b c d e f g

a - Section Numberb - Section Partc - Page Numberd - Manual Part Numbere - Revision Numberf - Month Printedg - Year Printed


90-861328--1 NOVEMBER 1999 Page 1A-3

How to Read a Parts Manual

Power Steering Pump Assembly

1

2

3 4

5

6

7

8

9

10

REF.NO. PART NO. SYM. QTY. DESCRIPTION

1 90507A12 1 PUMP ASSEMBLY–Power Steering2 36- 95805 1 CAP3 73873A1 1 PULLEY4 16- 41877 1 STUD5 57- 65607T 1 V-BELT6 32- 806684 1 HOSE–Pressure (FITTINGS ON BOTH ENDS)7 25- 89879 1 O-RING8 25- 806232 1 O-RING9 13- 35048 1 LOCKWASHER (3/8 in.)10 61990 1 CABLE TIE

REF. NO. : Number shown next to part on exploded view

PART NO. : Mercury Part Number for ordering. If NSS (not sold separately) sometimes GMpart number will be given in description column.

QTY. : The quantity that must be ordered.

DESCRIPTION : Description of part, what parts are included with a part (all indented itemscome with the main item above the indented parts), serial number information, and specialinformation.


Page 1A-4 90-861328--1 NOVEMBER 1999

Directional References

Front of boat is bow; rear is stern. Starboard side is right side; port side is left side. In thismanual, all directional references are given as they appear when viewing boat from sternlooking toward bow.

72000

STARBOARD(RIGHT)

PORT(LEFT)

FORE or BOW(FRONT)

AFT or STERN(REAR)

Engine Rotation

Engine rotation is determined by observing flywheel rotation from the rear (stern end) of theengine looking forward (toward water pump end). Propeller rotation is not necessarily thesame as engine rotation. When ordering replacement engine, short blocks or parts forengine, be certain to check engine rotation. Do not rely on propeller rotation in determiningengine rotation.

72001

Left Hand Rotation


90-861328--1 NOVEMBER 1999 Page 1A-5

Engine Serial Number Location

72975

a

b

a - Serial Number Plateb - Starter Motor

Propeller Information

Refer to the “Propeller” section in appropriate Mercury MerCruiser Sterndrive ServiceManual, or order publication 90-8614492, “What You Should Know About QuicksilverPropellers.”

Changing diameter, pitch or coupling of a propeller will affect engine rpm and boatperformance. The blade configuration also will affect performance. Two like propellers,same pitch and diameter, from two different manufacturers also will perform differently.

It is the responsibility of the boat manufacturer and/or selling dealer to equip the boat withthe correct propeller to allow the engine to operate within its specified rpm range at wideopen throttle (WOT).

Because of the many variables of boat design and operation, only testing will determine thebest propeller for the particular application.

To test for correct propeller, operate boat (with an average load onboard) at WOT and checkrpm with an accurate tachometer. Engine rpm should be near top of the specified range sothat, under heavy load, engine speed will not fall below specifications.

If engine exceeds the specified rpm, an increase in pitch and/or diameter is required.

If engine is below rated rpm, a decrease in pitch and/or diameter is required.

Normally, a change of approximately 200 rpm will be achieved for each one inch pitchchange of a propeller.

CAUTIONIf a propeller is installed that does not allow engine rpm to reach the specifiedfull-throttle rpm range, the engine will “labor” and will not produce full power.Operation under this condition will cause excessive fuel consumption, engineoverheating and possible piston damage (due to detonation). On the other hand,installation of a propeller, that allows engine to run above the specified rpm limit,will cause excessive wear on internal engine parts which will lead to prematureengine failure.


Page 1A-6 90-861328--1 NOVEMBER 1999

Water Testing New Engines

Use care during the first 20 hours of operation on new Mercury MerCruiser engines orpossible engine failure may occur. If a new engine has to be water-tested at full throttlebefore the break-in period is complete, follow this procedure.

1. Start engine and run at idle rpm until normal operating temperature is reached.

2. Run boat up on plane.

3. Advance engine rpm (in 200 rpm increments) until engine reaches its maximum ratedrpm.

IMPORTANT: Do not run at maximum rpm for more than 2 minutes.

Boat and Engine Performance

Boat BottomFor maximum speed, a boat bottom should be as flat as possible in a fore-aft direction(longitudinally) for approximately the last 5 ft (1.5 m).

72002

a

a - Critical Bottom Area

For best speed and minimum spray, the corner between the bottom and the transom shouldbe sharp.

72003a

bc

a - Bottomb - Cornerc - Transom


90-861328--1 NOVEMBER 1999 Page 1A-7

The bottom is referred to as having a “hook” if it is concave in the fore-and-aft direction. Ahook causes more lift on the bottom near the transom and forces the bow to drop. Thisincreases wetted surface and reduces boat speed. A hook, however, aids in planing andreduces any porpoising (rhythmical bouncing) tendency. A slight hook is often built in by themanufacturer. A hook also can be caused by incorrect trailering or storing the boat withsupport directly under the transom.

72004a

a - Hook

A “rocker” is the reverse of a hook. The bottom is convex or bulged in the fore-and-aftdirection. It can cause the boat to porpoise.

72005a

a - Rocker

Any hook, rocker or surface roughness on the bottom, particularly in the all-importantcenter-aft portion will have a negative effect on speed, often several miles per hour on a fastboat.

Marine FoulingFouling is an unwanted build-up (usually animal-vegetable-derived) occurring on the boat’sbottom and drive unit. Fouling adds up to drag, which reduces boat performance. In freshwater, fouling results from dirt, vegetable matter, algae or slime, chemicals, minerals andother pollutants. In salt water, barnacles, moss and other marine growth often producedramatic build-up of material quickly. Therefore, it is important to keep the hull as clean aspossible in all water conditions to maximize boat performance.

Antifouling paint, if required, may be applied to boat hull observing the following precautions.

IMPORTANT: DO NOT paint anodes or MerCathode System reference electrode andanode, as this will render them ineffective as galvanic corrosion inhibitors.

CAUTIONAvoid corrosion damage. Do not apply antifouling paint to Mercury MerCruiserdrive unit or transom assembly.


Page 1A-8 90-861328--1 NOVEMBER 1999

IMPORTANT: If antifouling protection is required, Tri-Butyl-Tin-Adipate (TBTA) baseantifouling paints are recommended on Mercury MerCruiser boating applications. Inareas where Tri-Butyl-Tin-Adipate base paints are prohibited by law, copper basepaints can be used on boat hull and boat transom. Corrosion damage that resultsfrom the improper application of antifouling paint will not be covered by the limitedwarranty. Observe the following:

Avoid an electrical interconnection between the Mercury MerCruiser Product,Anodic Blocks, or MerCathode System and the paint by allowing a minimum of 1-1/2in. (40mm) UNPAINTED area on transom of the boat around these items.

71176a b

a - Anti-Fouling Paintb - Minimum 1-1/2 in. (40 mm) UNPAINTED Area

Weight DistributionWeight distribution is extremely important; it affects a boat’s running angle or attitude. Forbest top speed, all movable weight - cargo and passengers - should be as far aft as possibleto allow the bow to come up to a more efficient angle (3 to 5 degrees). On the negative sideof this approach is the problem that, as weight is moved aft, some boats will begin anunacceptable porpoise.

Secondly, as weight is moved aft, getting on plane becomes more difficult.

Finally, the ride in choppy water becomes more uncomfortable as the weight goes aft. Withthese factors in mind, each boater should seek out what weight locations best suit his/herneeds.

Weight and passenger loading placed well forward increases the “wetted area” of the boatbottom and, in some cases, virtually destroys the good performance and handlingcharacteristics of the boat. Operation in this configuration can produce an extremely wetride, from wind-blown spray, and could even be unsafe in certain weather conditions orwhere bow steering may occur.

Weight distribution is not confined strictly to fore and aft locations, but also applies to lateralweight distribution. Uneven weight concentration to port or starboard of the longitudinalcenterline can produce a severe listing attitude that can adversely affect the boat’sperformance, handling ability and riding comfort. In extreme rough water conditions, thesafety of the boat and passengers may be in jeopardy.


90-861328--1 NOVEMBER 1999 Page 1A-9

Water in BoatWhen a boat loses performance, check bilge for water. Water can add considerable weightto the boat, thereby decreasing the performance and handling.

Make certain that all drain passages are open for complete draining.

Elevation and ClimateElevation has a very noticeable effect on the wide-open-throttle power of an engine. Sinceair (containing oxygen) gets thinner as elevation increases, the engine begins to starve forair. Humidity, barometric pressure and temperature do have a noticeable effect on thedensity of air. Heat and humidity thin the air. This phenomenon can become particularlyapparent when an engine is propped out on a cool dry day in spring and later, on a hot, humidday in August, does not have the same performance. See chart below.

Although some performance can be regained by dropping to a lower pitch propeller, thebasic problem still exists. The propeller is too large in diameter for the reduced power output.The experienced marine dealer or a Quicksilver Propeller Repair Station can determine howmuch diameter to remove from a lower-pitch propeller for specific high-elevation locations.In some cases, a gear-ratio change to the drive unit to more reduction is possible and verybeneficial. It is a known fact that weather conditions exert a profound effect on power outputof internal combustion engines. Therefore, established horsepower ratings refer to thepower that the engine will produce at its rated rpm under a specific combination of weatherconditions.

72006


Page 1A-10 90-861328--1 NOVEMBER 1999

THIS PAGE IS INTENTIONALLY BLANK

1B

MAINTENANCESERVICE MANUAL NUMBER 25

90-861328--1 NOVEMBER 1999 Page 1B-1

IMPORTANT INFORMATIONSection 1B - Maintenance

Table of Contents

Tools 1B-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Lubricants / Sealants / Adhesives 1B-2. . . . . Maintenance Schedules 1B-3. . . . . . . . . . . . . .

Maintenance Intervals 1B-3. . . . . . . . . . . . . Gas Sterndrive 1B-3. . . . . . . . . . . . . . . . . . . . . .

Routine Maintenance * 1B-3. . . . . . . . . . . . Scheduled Maintenance * 1B-4. . . . . . . . . .

Engine and Tune-Up Specifications 1B-5. . . . MCM (Sterndrive) 1B-5. . . . . . . . . . . . . . . . .

Fluid Capacities 1B-6. . . . . . . . . . . . . . . . . . . . . Sterndrive Engines 1B-6. . . . . . . . . . . . . . . Sterndrives 1B-6. . . . . . . . . . . . . . . . . . . . . .

20-Hour Break-In Period 1B-7. . . . . . . . . . . . . After Break-in Period 1B-7. . . . . . . . . . . . . . . . End of First Season Checkup 1B-7. . . . . . . . . Specifications 1B-8. . . . . . . . . . . . . . . . . . . . . . .

Fuel Recommendations 1B-8. . . . . . . . . . . Test For Alcohol Content In Gasoline 1B-10

Power Steering Fluid 1B-10. . . . . . . . . . . . . . . . Coolant for Closed Cooling System 1B-10. . . . Crankcase Oil 1B-11. . . . . . . . . . . . . . . . . . . . . .

Overfilled Crankcase Oil 1B-11. . . . . . . . . . . Checking Engine Oil Level / Filling 1B-12. .

Changing Oil and Filter 1B-12. . . . . . . . . . . . . . . Changing Water Separating Fuel Filter 1B-13. Power Steering System 1B-15. . . . . . . . . . . . . .

Checking Fluid Level 1B-15. . . . . . . . . . . . . . Engine Cold 1B-15. . . . . . . . . . . . . . . . . . . . . Filling and Bleeding 1B-16. . . . . . . . . . . . . . .

Closed Cooling System 1B-17. . . . . . . . . . . . . . Checking Coolant Level 1B-17. . . . . . . . . . . Flushing System 1B-18. . . . . . . . . . . . . . . . . .

Lubrication 1B-20. . . . . . . . . . . . . . . . . . . . . . . . . Throttle Cable 1B-20. . . . . . . . . . . . . . . . . . . . Shift Cable 1B-20. . . . . . . . . . . . . . . . . . . . . . . Engine Coupler / U-Joint Shaft Splines 1B-21. . . . . . . . . . . . . Sterndrive Drive Shaft Extension Models 1B-22. . . . . . . . . . .

Cleaning Flame Arrestor 1B-22. . . . . . . . . . . . . Top Mounted Flame Arrestor 1B-23. . . . . . .

Serpentine Drive Belt 1B-23. . . . . . . . . . . . . . . . Component Location 1B-23. . . . . . . . . . . . . .

Serpentine Belt Routing 1B-24. . . . . . . . . . . . . . S/N 0L619083 and Below 1B-24. . . . . . . . . . S/N 0L619084 and Above 1B-25. . . . . . . . . Inspection 1B-26. . . . . . . . . . . . . . . . . . . . . . . Replacing and/or Adjusting Tension 1B-26.

Ignition Timing 1B-27. . . . . . . . . . . . . . . . . . . . . . Thunderbolt V Models 1B-27. . . . . . . . . . . . . EFI 1B-28. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Cold Weather or Extended Storage 1B-29. . . . Precautions 1B-29. . . . . . . . . . . . . . . . . . . . . . Power Package Layup 1B-31. . . . . . . . . . . . Draining Instructions 1B-33. . . . . . . . . . . . . . Draining Sterndrive 1B-38. . . . . . . . . . . . . . . Recommissioning 1B-39. . . . . . . . . . . . . . . . .

MAINTENANCE SERVICE MANUAL NUMBER 25

Page 1B-2 90-861328--1 NOVEMBER 1999

Tools

Description Part Number

Timing Light 91-99379

Quicksilver Scan Tool 91-823686A2

Lubricants / Sealants / Adhesives


Quicksilver Liquid Neoprene 92-25711--3

Quicksilver 2-4-C Marine Lubricant With Teflon 92-825407A3

Loctite Pipe Sealant With Teflon Obtain Locally

Quicksilver U-Joint and Gimbal Bearing Grease 92-828052A2


90-861328--1 NOVEMBER 1999 Page 1B-3

Maintenance Schedules

Maintenance IntervalsMaintenance intervals and the tasks to be performed, as shown in this current schedule, oras found in a previously printed schedules, are generally based on an average boatingapplication and environment. However, individual operating habits and personal mainte-nance preferences can have an impact on the suggested intervals. In consideration of thesefactors, Mercury MerCruiser has adjusted some maintenance intervals and correspondingtasks to be performed. In some cases, this may allow for more individual tasks to beperformed in a single visit to the serving dealer, rather than multiple visits. Therefore, it isvery important that the boat owner and servicing dealer discuss the current MaintenanceSchedule and develop appropriate maintenance intervals to coincide with the individualoperating habits, environment, and maintenance requirements.

CAUTIONAlways disconnect battery cables from battery BEFORE working around electricalsystems components to prevent injury to yourself and damage to electrical systemshould a wire be accidentally shorted.

Gas SterndriveRoutine Maintenance *

EachDayStart

EachDayEnd

WeeklyEveryTwo

Months

Check crankcase oil (interval can be extended based on experi-ence).

��

If operating in salt, brackish or polluted waters, flush cooling sys-tem after each use.

��

Check drive unit oil level, trim pump oil level and power steeringpump fluid level.

��

Check water pickups for debris or marine growth. Check waterstrainer and clean. Check coolant level.

��

Inspect drive unit anodes and replace if 50 percent eroded. ��

Inspect fuel pump sight tube and have pump replaced if fuel ispresent.

��

Check battery connections and fluid level. ��

Lubricate propeller shaft and the retorque nut (if operating in onlyfreshwater, this maintenance may be extended to every fourmonths).

��

Operating in Saltwater Only: treat engine surface with corrosionguard.

��

Clean air filter every 50 hours of operation. ��

* Only perform maintenance which applies to your particular power package

� Standard Models

� Horizon Models


Page 1B-4 90-861328--1 NOVEMBER 1999

Gas Sterndrive(Continued)Scheduled Maintenance *

Annu-ally

Every100

hours orAnnually

Every200

hoursor 3

years

Every300

hoursor 3

years

Every2

years

Every5

years

Touch-up paint power package and spray with corrosionguard.

��

Change crankcase oil and filter. ��

Change drive unit oil and retorque connection of gimbalring to steering shaft.

��

Replace fuel filter(s). ��

Check steering system and remote control for loose,missing or damaged parts. Lubricate cables and link-ages.

��

Inspect U-joints, splines and bellows. Check clamps.Check engine alignment. Lubricate U-joints splines.

� �

Lubricate gimbal bearing and engine coupler. ��

Check continuity circuit for loose or damaged connec-tions. Test MerCathode� unit output on Bravo Models. � �

Retorque engine mounts. � �

Check spark plugs, wires, distributor cap and ignitiontiming. Check and adjust idle speed.

� �

Clean flame arrestor and crankcase ventilation hoses.Replace PCV valve.

� �

Check electrical system for loose, damaged or corrodedfasteners.

� �

Inspect condition and tension of belts. � �

Check cooling system and exhaust system hose clampsfor tightness. Inspect both systems for damage or leaks.

� �

Disassemble and inspect seawater pump and replaceworn components.

� �

Clean seawater section of closed cooling system.Clean, inspect and test pressure cap.

� �

Replace coolant. � ��

* Only perform maintenance which applies to your particular power package

� Standard Models

� Horizon Models

� Whichever Occurs First

� Interval will be reduced if not using extended life coolant.

� Lubricate engine coupler every 50 hours if operated at idle for prolonged periods of time.


90-861328--1 NOVEMBER 1999 Page 1B-5

Engine and Tune-Up Specifications

MCM (Sterndrive)

ModelMCM 4.3LALPHA /BRAVO

MCM 4.3LHALPHA /BRAVO

MCM 4.3LEFI

ALPHA /BRAVO

Propshaft Horsepower(SAV1 Rating)

190 205 (190)2 2101 (188)2

Propshaft Kilowatts (SAV1 Rating) 142 153 (142)2 1571 (146)2

Number of Cylinders V-6

Displacement 262 cid (4.3 l)

Bore / Stroke - in. (mm) 4.0 x 3.48 (101.6 x 88.4)

Compression Ratio 9.4:1 9.4:1

Compression Pressure Minimum 100 psi (690 kPa)7

Idle rpm In Neutral3 650 rpm5 600 rpm5

Maximum rpm (at WOT)3 4400-4800 rpm

Oil Pressure (at 2000 rpm) Minimum 30 psi (207 kPa)

Minimum Oil Pressure (at Idle) Minimum 4 psi (28 kPa)

Fuel Pressure (1800 rpm) 3-7 psi (21-48 kPa) 30 psi ( kPa)

Electrical System 12 V Negative (–) Ground

Alternator Rating 55 or 65 amp 8

Minimum Battery Requirements 375 cca / 475 mca / 90 Ah

Firing Order 1-6-5-4-3-2

Spark Plug TypeAC - MR43LTS

Champion - RS12YCNGK - BPR6EFS

Spark Plug Gap .045 in. (1.1 mm)

Timing (at idle rpm)4 10° BTDC 8° BTDC

Preliminary Idle Mixture 1 1/4 Turns DNA

Thermostat 160° F (71° C)

1 Power Rated in Accordance with NMMA (National Marine Manufacturers’ Association) rating procedures.2 Power Rated in Accordance with SAV1 rating procedures. This rating procedure is used to certify that theengine complies with “Stage 1” Bodensee and Swiss Regulations. Horsepower differences shown result fromdifferences in test rpm, allowable test tolerances, and/or installation of special kit components.3 Measured using an accurate service tachometer with engine at normal operating temperature.4 Timing must be set using a special procedure as outlined in the appropriate section of this manual. Timing can-not be properly set using the conventional method.5 A special procedure must be followed to adjust idle rpm. Consult your Authorized Mercury MerCruiser Dealerbefore attempting this procedure.6 Idle speed on EFI models is not adjustable.7 Minimum recorded compression in any one cylinder should not be less than 70 percent of the highest recordedcylinder.8 Serial Number Break for 65 Amp alternator: OL619083 and above.


Page 1B-6 90-861328--1 NOVEMBER 1999

Fluid Capacities

NOTICE

Unit Of Measurement: U.S. Quarts (Liters)All capacities are approximate fluid measures.

Sterndrive Engines

Model All Models

Crankcase Oil (With Filter) 1 4-1/2 (4.3)

Seawater Cooling System 2 15 (14.1)

Closed Cooling System 20 (19)

1 Always use dipstick to determine exact quantity of oil or fluid required.2 Seawater Cooling System capacity information is for winterization use only.

Sterndrives

NOTICE

Unit Of Measurement: U.S. Fluid Ounces (Milliliters)All capacities are approximate fluid measures.

Model ALPHA ONE

Drive Unit Oil Capacity (With Gear Lube Monitor) 64 (1892)

Model BRAVO ONE BRAVO TWO BRAVO THREE

Drive Unit Oil Capacity(With Gear Lube Monitor)

88 (2603) 104 (3076) 96 (2839)


90-861328--1 NOVEMBER 1999 Page 1B-7

20-Hour Break-In Period

IMPORTANT: The first 20 hours of operation is the engine break-in period. Correctbreak-in is essential to obtain minimum oil consumption and maximum engine per-formance. During this break-in period, the following rules must be observed:• Do not operate below 1500 rpm for extended periods of time for first 10 hours. Shift into

gear as soon as possible after starting and advance throttle above 1500 rpm if condi-tions permit safe operation.

• Do not operate at one speed consistently for extended periods.

• Do not exceed 3/4 throttle during first 10 hours. During next 10 hours, occasional opera-tion at full throttle is permissible (5 minutes at a time maximum).

• Avoid full throttle acceleration from IDLE speed.

• Do not operate at full throttle until engine reaches normal operating temperature.

After Break-in Period

To help extend the life of your Mercury MerCruiser power package, the following recommen-dations should be considered:• Use a propeller that allows the engine to operate at or near the top of the maximum rpm

range (refer to “Specifications” section) when at full throttle with a normal boat load.

• Operation at 3/4 throttle setting or lower is recommended. Refrain from prolonged op-eration at maximum (full throttle) rpm.

End of First Season Checkup

At the end of the first season of operation, an Authorized Mercury MerCruiser Dealer shouldbe contacted to discuss and/or perform various scheduled maintenance items. If you arein an area where the product is operated continuously (year-round operation), you shouldcontact your dealer at the end of the first 100 hours of operation, or once yearly, whicheveroccurs first.


Page 1B-8 90-861328--1 NOVEMBER 1999

CA261

Specifications

Fuel RecommendationsIMPORTANT: Use of improper gasoline can damage your engine seriously. Enginedamage resulting from use of improper gasoline is considered misuse of engine, anddamage caused thereby will not be covered under the limited warranty.

FUEL RATINGS

Mercury MerCruiser engines will operate satisfactorily when using a major brand ofunleaded gasoline as follows:

USA and Canada - having a posted pump Octane Rating of 87 (R+M)/2 minimum. Premiumgasoline [92 (R+M)/2 Octane] is also acceptable. DO NOT use leaded gasoline.

Outside USA and Canada - having a posted pump Octane Rating of 90 RON minimum.Premium gasoline (98 RON) is also acceptable. If unleaded gasoline is not available, usea major brand of leaded gasoline.

CA291

USING REFORMULATED (OXYGENATED) GASOLINES (USA ONLY)

This type of gasoline is required in certain areas of the USA. The two types of “oxygenates”used in these fuels are Alcohol (Ethanol) or Ether (MTBE or ETBE). If Ethanol is the “oxygen-ate” that is used in the gasoline in your area, refer to “Gasolines Containing Alcohol.”

These “Reformulated Gasolines” are acceptable for use in your Mercury MerCruiserengine.

VAPOR LOCKING

Fuels containing alcohol and winter grade fuels will aggravate vapor lock problems. A vaporlock condition can be identified by the following problems:• Engine starts and, upon advancing throttle, shuts off and will not restart.

• If engine does restart, it shuts off when advancing throttle.

• Engine is difficult to restart after operating the boat and then leaving the engine off for 1 to3 hours.

Other factors may combine to increase vapor locking. These factors include but are not lim-ited to:• air temperature

• fuel tank location

• fuel supply system

• engine coolant temperature

• temperature and vacuum of fuel to engine

• engine compartment air temperature and ventilation

Other conditions should be ruled out before treating the problem as vapor locking.


90-861328--1 NOVEMBER 1999 Page 1B-9

CA618

GASOLINES CONTAINING ALCOHOL

If the gasoline in your area contains either “methanol” (methyl alcohol) or “ethanol” (ethylalcohol), you should be aware of certain adverse effects that can occur. These adverseeffects are more severe with “methanol.” Increasing the percentage of alcohol in the fuel canalso worsen these adverse effects.

Some of these adverse effects are caused because the alcohol in the gasoline can absorbmoisture from the air, resulting in a separation of the water/alcohol from the gasoline in thefuel tank.

The fuel system components on your Mercury MerCruiser engine will withstand up to 10%alcohol content in the gasoline. We do not know what percentage your boat’s fuel systemwill withstand. Contact your boat manufacturer for specific recommendations on the boatsfuel system components (fuel tanks, fuel lines and fittings). Be aware that gasolinescontaining alcohol may cause increased:• Corrosion of metal parts.

• Deterioration of rubber or plastic parts.

• Fuel permeation through rubber fuel lines.

• Starting and operating difficulties.

WARNINGFIRE AND EXPLOSION HAZARD: Fuel leakage from any part of fuel system can bea fire and explosion hazard which can cause serious bodily injury or death. Carefulperiodic inspection of entire fuel system is mandatory, particularly after storage. Allfuel components including fuel tanks, whether plastic metal or fiberglass, fuellines, fittings, fuel filters and carburetors/fuel injection components should be in-spected for leakage, softening, hardening, swelling or corrosion. Any sign of leak-age or deterioration requires replacement before further engine operation.

Because of possible adverse effects of alcohol in gasoline, it is recommended that only alco-hol-free gasoline be used where possible. If only fuel containing alcohol is available, or ifthe presence of alcohol is unknown, increased inspection frequency for leaks and abnorma-lities is required.

IMPORTANT: When operating a Mercury MerCruiser engine on gasoline containingalcohol, storage of gasoline in the fuel tank for long periods should be avoided. Longperiods of storage, common to boats, create unique problems. In cars alcohol-blendfuels normally are consumed before they can absorb enough moisture to causetrouble, but boats often sit idle long enough for phase separation to take place. Inaddition, internal corrosion may take place during storage if alcohol has washed pro-tective oil films from internal components.


Page 1B-10 90-861328--1 NOVEMBER 1999

Test For Alcohol Content In GasolineThe following is an acceptable and widely used field procedure for the detection of alcoholin gasoline. Use any small transparent bottle or tube that can be capped and is, or can be,provided with graduations or a mark at about 1/3 full. A pencil mark on a piece of adhesivetape may be used.

PROCEDURE

1. Fill the container with water to the mark.

2. Add fuel almost to fill the container, leaving some air space, then cap the container. Theproportions of fuel to water are not critical, but there should be 2 to 3 times as much fuelas water.

3. Shake container vigorously and allow it to sit upright for 3 to 5 minutes. If the volumeof water appears to have increased, alcohol is present. If you are not sure, there is noneed for concern. If the dividing line between water and fuel becomes cloudy, use themiddle of the cloudy band.

Power Steering Fluid

Use Quicksilver Power Trim and Steering Fluid or automatic transmission Fluid (ATF)Dexron III.

Coolant for Closed Cooling System

CAUTIONAlcohol or Methanol base antifreeze or plain water, are not recommended for usein fresh water section of cooling system at any time.

We recommend that the coolant section of closed cooling system be filled with ExtendedLife Ethylene Glycol 5/100 Antifreeze/Coolant mixed 50/50 with purified water. In areaswhere the possibility of freezing does not exist, it is permissible to use a solution of rust inhi-bitor and water (mixed to manufacturer’s recommendations).

If any non-compatible coolant is added to this coolant, coolant must be changed every 2years or 400 hours, whichever occurs first. All coolants other than Extended Life 5/100Ethylene Glycol Antifreeze/Coolant must be changed every 2 years or 400 hours, whicheveroccurs first.

Mercury MerCruiser V-8 engines can use any type of permanent antifreeze or any brandantifreeze solution that meets GM specification 1825M.


90-861328--1 NOVEMBER 1999 Page 1B-11

CA693

Crankcase Oil

To help obtain optimum engine performance and to provide maximum protection, westrongly recommend the use of Quicksilver 4-Cycle 25W-40 Marine Engine Oil. This oil isa special blend of 25-weight and 40-weight oils for marine engines. If not available, a goodgrade, straight weight, detergent automotive oil of correct viscosity, with an APIclassification of SH,CF/CF-2, may be used.

In those areas where Quicksilver 4-Cycle 25W-40 Marine Engine Oil or a recommendedstraight weight oil are not available, a multiviscosity 20W-40 (SH, CF/CF-2) or, as a secondbut less preferable choice, 20W-50, with API service ratings of SH, CF/CF-2 may be used.

IMPORTANT: The use of non-detergent oils, multi-viscosity oils (other than Quicksil-ver 25W-40 or a good quality 20W-40 or 20W-50), synthetic oils, low quality oils or oilsthat contain solid additives are specifically not recommended.

The chart below is a guide to crankcase oil selection. The oil filter should always be changedwith oil.

70534

Quicksilver 4-Cycle Marine Engine Oil

SAE 20W

SAE 30W

SAE 40W

32° F0° C

50° F10° C

AIR TEMPERATURE

Overfilled Crankcase OilOverfilled crankcases (oil level being too high ) can cause a fluctuation or drop in oil pressureand rocker arm “clatter” on Mercury MerCruiser engines. The over-full condition results inthe engine crankshaft splashing and agitating the oil, causing it to foam (become aerated).The aerated oil causes the hydraulic valve lifters to “bleed down.” This, in turn, results inrocker arm “clatter” and loss of engine performance, due to the valves not opening properly.

Care must be taken when checking engine oil level. Oil level must be maintained betweenthe ADD mark and the FULL mark on the dipstick. To ensure that you are not getting a “falsereading,” make sure the following steps are done before checking the oil level.• Boat “at rest” in the water, or

• If boat is on a trailer, raise or lower bow until the boat is setting at the approximate anglethat it would be if setting “at rest” in the water.

• Allow sufficient time for oil to drain into the crankcase if engine has just been run or oilhas just been added.


Page 1B-12 90-861328--1 NOVEMBER 1999

Checking Engine Oil Level / FillingIMPORTANT: ENGINE CRANKCASE OIL MUST BE CHECKED AT INTERVALSSPECIFIED IN “MAINTENANCE SCHEDULE” CHART. It is normal for an engine to usea certain amount of oil in the process of lubrication and cooling of the engine. Theamount of oil consumption is greatly dependent upon engine speed, withconsumption being highest at wide-open-throttle and decreasing substantially asengine speed is reduced.

1. Stop engine and allow boat to come to a rest.

2. Allow oil to drain back into oil pan - approximately 5 minutes.

3. Remove dipstick.

4. Wipe clean and reinstall. Push dipstick all the way into dipstick tube.

5. Remove dipstick and note the oil level.

6. Oil level must be between the FULL or OP RANGE and ADD marks.

7. If oil level is below ADD mark, proceed to Steps 8. and 9.

8. Remove oil filler cap from valve rocker arm cover.

9. Add required amount of oil to bring level up to, but not over, the FULL mark on dipstick.

Changing Oil and Filter

1. Start engine and run until it reaches normal operating temperatures.

IMPORTANT: Change oil when engine is warm from operation, as it flows more freely,carrying away more impurities.

2. Stop engine.

3. Remove drain plug from oil pan or from oil drain hose.

IMPORTANT: If engine is factory equipped with Quick Drain Oil Hose, pull tetherthrough bilge drain before removing drain plug from oil drain hose.

NOTE: If drain plug is not accessible because of boat construction, oil may be removedthrough dipstick tube, using a Quicksilver Crankcase Oil Pump. (See Quicksilver AccessoryGuide.)

4. After oil has drained completely, reinstall drain plug (if removed) and tighten securely.

5. Remove and discard oil filter and its sealing ring.

6. Coat sealing ring on new filter with engine oil and install. Tighten filter securely (followingfilter manufacturer’s instructions). Do not overtighten.

7. Fill crankcase with oil. See “Specifications” for type of oil and quantity.

8. Check dipstick to ensure oil level is up to, but not over, FULL or OP RANGE mark ondipstick.

9. Start engine and check for leaks.


90-861328--1 NOVEMBER 1999 Page 1B-13

Changing Water Separating Fuel Filter

WARNINGBe careful when changing water separating fuel filter. Gasoline is extremelyflammable and highly explosive under certain conditions. Be sure ignition key isOFF. Do not smoke or allow spark or open flame in area when changing fuel filter.Wipe up any spilled fuel immediately.

WARNINGMake sure no fuel leaks exist before closing engine hatch.

CAUTIONThe electric fuel pump and factory installed water separating fuel filter have beencarefully designed to function properly together. Do not install additional fuel filtersand/or water separating fuel filters between fuel tank and engine.

The installation of additional filters may cause:• Fuel Vapor Locking

• Difficult Warm-Starting

• Piston Detonation Due to Lean Fuel Mixture

• Poor Driveability

1. Unsnap latch and slide top and bottom cover pieces, if equipped, from around the waterseparating fuel filter and bracket.

75034

a

a - Fuel Filter Cover

NOTE: Top and bottom cover pieces are formed with a groove on each side that slidesaround the brackets outer edges.


Page 1B-14 90-861328--1 NOVEMBER 1999

2. Remove water separating fuel filter and sealing ring from mounting bracket and discard.

70573

b

a

a - Fuel Filterb - Sealing Ring

3. Coat sealing ring on new filter with motor oil.

4. Thread filter onto bracket and tighten securely by hand. Do not use a filter wrench.

5. Start and run engine.

6. Check filter connection for gasoline leaks. If leaks exist, recheck filter installation.

7. Install cover pieces around fuel filter. Be certain top part of cover latches to lower part.


90-861328--1 NOVEMBER 1999 Page 1B-15

Power Steering SystemChecking Fluid Level

ENGINE WARM

1. Stop engine. Position drive unit so that it is straight back.

2. Remove fill cap / dipstick from power steering pump and note fluid level.

74908

a b

a - Fill Cap / Dipstickb - Power Steering Pump

3. Level should be between the FULL HOT mark and ADD mark on dipstick.

72518a

a - Proper Fluid Level with Engine Warm

4. If level is below ADD mark, but fluid is still visible in pump reservoir, add required amountof Quicksilver Power Trim and Steering Fluid or automatic transmission fluid (ATF) Dex-ron III through fill cap opening, to bring level up to FULL HOT mark on dipstick. DO NOTOVERFILL.

5. If fluid is not visible in reservoir, a leak exists in the power steering system. Find causeand correct.

Engine Cold1. With engine stopped, position drive unit so that it is straight back.

2. Remove fill cap / dipstick from power steering pump and note fluid level.

3. Level should be between FULL COLD mark and bottom of dipstick.

72519a

a - Proper Fluid Level with Engine Cold

4. If level is below bottom of dipstick, but fluid is still visible in pump reservoir, add requiredamount of Quicksilver Power Trim and Steering Fluid or automatic Dexron III transmis-sion fluid (ATF), through fill cap opening, to bring level up to FULL COLD mark on dip-stick. DO NOT OVERFILL.

If fluid is not visible in reservoir, a leak exists in the power steering system. Find cause andcorrect.


Page 1B-16 90-861328--1 NOVEMBER 1999

Filling and BleedingIMPORTANT: Power steering system must be filled exactly as explained in the follow-ing to be sure that all air is bled from the system. All air must be removed, or fluid inpump may foam during operation and be discharged from pump reservoir. Foamyfluid also may cause power steering system to become spongy, which may result inpoor boat control.

1. With engine stopped, position drive unit so that it is straight back.

2. Remove fill cap / dipstick from power steering pump.

3. Add Quicksilver Power Trim and Steering Fluid or Dexron III automatic transmissionfluid (ATF), as required, to bring level up to FULL COLD mark on dipstick.

IMPORTANT: Use only Quicksilver Power Trim and Steering Fluid or Dexron III auto-matic transmission fluid (ATF), in power steering system.

4. Turn steering wheel back and forth to end of travel in each direction several times.

5. Recheck fluid level and add fluid, if necessary.

6. Install vented fill cap. Tighten securely.

CAUTIONDO NOT operate engine without water being supplied to seawater pickup pump, orpump impeller may be damaged and subsequent overheating damage to enginemay result.

7. Start engine and run at fast idle (1000-1500 rpm) until engine reaches normal operatingtemperature. During this time, turn steering wheel back and forth to end of travel in eachdirection several times.

8. Position drive unit so that it is straight back and stop engine.

9. Remove fill cap from pump.

10. Allow any foam in pump reservoir to disperse.

11. Check fluid level and add fluid, as required, to bring level up to FULL HOT mark on dip-stick. DO NOT OVERFILL.

12. Reinstall fill cap. Tighten securely.

IMPORTANT: Drive unit must be positioned straight back and power steering fluidmust be hot to accurately check fluid level.

13. If fluid is still foamy (in Step 5.), repeat Steps 7. through 12. until fluid does not foam andlevel remains constant.


90-861328--1 NOVEMBER 1999 Page 1B-17

Closed Cooling System

Checking Coolant Level

CAUTIONAllow engine to cool down before removing pressure cap. Sudden loss of pressurecould cause hot coolant to boil and discharge violently. After engine has cooled,turn cap 1/4 turn to allow any pressure to escape slowly, then push down and turncap all the way off.

1. Coolant level in heat exchanger should be full (to bottom of filler neck).

IMPORTANT: When reinstalling pressure cap, be sure to tighten it until it contacts onfiller neck.

2. Coolant level should be between the ADD and FULL marks on coolant recovery reser-voir with the engine at normal operating temperature.

72520

a

a - Coolant Recovery Reservoir


Page 1B-18 90-861328--1 NOVEMBER 1999

Flushing SystemIf engine is operated in salty, polluted or mineral-laden water, flush seawater cooling system(preferably after each use) to reduce corrosion and prevent the accumulation of depositsin the system. Thoroughly flush the seawater cooling system prior to storage.

NOTE: For additional protection against freezing and rust to the exhaust manifolds andother components, a 50-50 mixture of antifreeze and water can be run through the engineduring Power Package Layup.

1. Install flushing attachment and water hose over the water pickup holes in gear housing.

72693

a

ba - Flushing Attachmentb - Hose

WARNINGWhen flushing, be certain the area around propeller is clear, and no one is standingnearby. To avoid possible injury, remove propeller.

CAUTIONDo not run engine above 1500 rpm when flushing. Suction created by seawater pick-up pump may collapse flushing hose, causing engine to overheat.

CAUTIONWatch temperature gauge on dash to ensure that engine does not overheat.

2. Open water tap enough to cool the engine, about � of its maximum capacity. Adjust asrequired so that the engine does not overheat.

3. With drive in neutral gear, start engine and advance the throttle until the engine reaches1300 rpm.

IMPORTANT: DO NOT run the engine at idle rpm. Watch engine temperature gaugeon dash. Do not run the engine above 1500 rpm or engine overheating may occur.

4. Run engine for 10 minutes or until the discharge water is clear.

5. Slowly return the throttle to the idle position and turn engine off.

IMPORTANT: DO NOT rapidly advance or return throttle as this can cause water in-gestion.


90-861328--1 NOVEMBER 1999 Page 1B-19

BOAT IN WATER

1. Raise drive unit to full UP / OUT position.

2. Install flushing attachment over water pickup holes in gear housing as shown.

3. Attach a water hose between the flushing attachment and a water tap.

72693

a

ba - Flushing Attachmentb - Hose

4. Lower drive unit to full DOWN / IN position.

CAUTIONDo not run engine above 1500 rpm when flushing. Suction created by seawater pick-up pump may collapse flushing hose, causing engine to overheat.

CAUTIONWatch temperature gauge on dash to ensure that engine does not overheat.

5. Partially open water tap (approximately 1/2 maximum capacity). DO NOT use full waterpressure.

6. Place remote control in neutral, idle speed position, and start engine.

7. Operate engine at idle speed in neutral for 10 minutes, then stop engine.

8. Shut off water tap.

9. Raise drive unit to full UP / OUT position.

10. Remove water hose and flushing attachment.


Page 1B-20 90-861328--1 NOVEMBER 1999

Lubrication

Throttle Cable1. Lubricate pivot points and guide contact surfaces with SAE 30W motor oil.

74941

b

a

a

a

a

b

71359

2 Barrel Carbureted Models EFI Modelsa - Pivot Pointsb - Guide Contact Surface

Shift Cable

MCM (STERNDRIVE) MODELS

1. Lubricate pivot points and guide contact surfaces with SAE 30W motor oil.

72016

b

b a

a

a

Typical Shift Cablea - Pivot Pointsb - Guide Contact Surface


90-861328--1 NOVEMBER 1999 Page 1B-21

Engine Coupler / U-Joint Shaft SplinesNOTE: Engine coupler and shaft splines are greased with Quicksilver Engine CouplerSpline Grease, 92-816391A4; universal joints are greased with Quicksilver 2-4-C MarineLubricant.

NOTE: Refer to Mercury MerCruiser Sterndrive Service Manual for sterndrive unit removaland installation, if necessary.

IMPORTANT: Sterndrive Unit does not have to be removed to grease coupler.

1. Lubricate engine coupler splines through grease fitting on coupler by applying approxi-mately 8-10 pumps of grease from a typical hand-operated grease gun.

71569a 72529

abb

Typical Alpha Drive Coupler Typical Bravo Drive Coupler

IMPORTANT: Later Bravo Models may be equipped with a coupler that is similar tothe Alpha Coupler.

a - Grease Fittingb - Quicksilver Engine Coupler Spline Grease

72531

a

a

a

Typical Bravo Drivea - Quicksilver Engine Coupler Spline Grease


Page 1B-22 90-861328--1 NOVEMBER 1999

Sterndrive Drive Shaft Extension Models

72018

a

a

72028

a

a

Transom End Engine Enda - Grease Fitting

Cleaning Flame Arrestor

WARNINGAvoid gasoline fire or explosion. Gasoline is extremely flammable and highlyexplosive under certain conditions. Be careful when cleaning flame arrestor andcrankcase ventilation hoses. Be sure that ignition is OFF. DO NOT smoke or allowsources of spark or open flame in area when cleaning flame arrestor and crankcaseventilation hoses.

WARNINGAvoid gasoline fire or explosion. Gasoline is extremely flammable and highly explo-sive under certain conditions. NEVER use gasoline as a cleaning solvent.


90-861328--1 NOVEMBER 1999 Page 1B-23

Top Mounted Flame Arrestor1. Remove flame arrestor cover.

2. Remove crankcase ventilation hose from fitting on side of flame arrestor housing.

3. Remove flame arrestor.

76501

a

a - Flame Arrestor

4. Clean flame arrestor in solvent. Blow dry with compressed air.

5. Clean crankcase ventilation hose in solvent. Blow dry with compressed air.

6. Inspect crankcase ventilation hose for cracks or deterioration and replace if necessary.

7. Reinstall flame arrestor and crankcase ventilation hose.

8. Reinstall flame arrestor cover.

Serpentine Drive Belt

Component Location

WARNINGAvoid possible serious injury. Make sure engine is shut off and ignition key isremoved before inspecting belt.

NOTE: Some models will have components arranged in a different order. All configurationsare not shown. Checking, replacing and adjustment procedures are the same.


Page 1B-24 90-861328--1 NOVEMBER 1999

Serpentine Belt Routing

S/N 0L619083 and Below

Alpha With Power Steering Bravo With Power Steering

Alpha With Closed Cooling Bravo Without Power SteeringWithout Power Steering

Alpha With Closed Cooling Bravo With Closed Coolingand Power Steering and Power Steering


90-861328--1 NOVEMBER 1999 Page 1B-25

Serpentine Belt Routing (Continued)

S/N 0L619084 and Above

7650276503

Alpha With Power Steering Bravo With Power Steering

7644576463

Alpha Without Power Steering Bravo Without Power Steering


Page 1B-26 90-861328--1 NOVEMBER 1999

Inspection1. Inspect drive belt for the following:• Excessive wear

• Cracks

NOTE: Minor, transverse cracks (across the belt width) may be acceptable. Longitudinalcracks (in direction of belt length) that join transverse cracks are NOT acceptable.• Fraying

• Glazed surfaces

75130

ba

a - Frayingb - Cracks

Replacing and/or Adjusting Tension

REMOVAL

1. Loosen 5/8 in. locking nut on adjustment stud.

2. Turn adjustment stud and loosen belt.

3. Remove drive belt.

INSTALLATION AND ADJUSTMENT

4. Install drive belt on pulleys.

5. Adjust tension by loosening 5/8 in. locking nut on adjustment stud. Leave wrench onadjustment stud.

NOTE: Belt deflection is to be measured on the belt at the location that has the longest dis-tance between two (2) pulleys. Proper tension is 1/4 in. (6 mm) deflection with moderatethumb pressure.

6. Use 5/16 in. socket and tighten adjusting stud until the correct deflection of the belt isobtained at location specified above.


90-861328--1 NOVEMBER 1999 Page 1B-27

7. While holding adjustment stud at the correct belt tension, tighten 5/8 in. locking nut.

8. Run engine for a short period of time and recheck belt adjustment.

74908

a

b

a - 5/8 in. Locking Nutb - 5/16 in. Adjusting Stud

Ignition Timing

Thunderbolt V Models1. Connect timing light to number 1 spark plug wire.

2. Connect a shop tachometer to the engine.

IMPORTANT: Before starting the engine, connect a jumper wire from the ignition tim-ing lead to a good ground. This has to be done before the ignition key is turned ONto lock the ignition module into Base Timing Mode.

3. Before starting the engine, connect jumper wire from timing lead to a good ground.

NOTE: The PUR/WHT timing lead is located towards the front of the engine near the fuelline or near the distributor, as equipped for your model.

4. Start engine and run at 1300 rpm until it reaches normal operating temperature.

5. Disconnect throttle cable from the carburetor.

6. With engine at idle rpm, adjust the carburetor idle rpm screw to the specified engine idlerpm.

7. With the engine still at idle rpm, check the ignition timing. If incorrect, rotate thedistributor until timing is correct. Torque clamping screw to 18 lb-ft (25 Nm).

8. Adjust the idle mixture screw. Inward is LEAN, outward is RICH.

9. Recheck ignition timing.

10. Stop engine. Remove timing light, jumper wire and shop tachometer.

IMPORTANT: Timing jumper wire has to be removed or the ignition module will staylocked in the Base Timing Mode and it will not be able to advance the ignition timingcorrectly when the engine rpm is increased.

11. Adjust and reinstall throttle cable. Open and close remote control throttle lever. Ensurethat the carburetor throttle lever is contacting the idle rpm adjusting screw every time.

12. Restart the engine, increase rpm to 1300 then return to idle position slowly and shut theengine off. Ensure that the carburetor throttle lever is contacting the idle rpm screw.

13. Shut engine off.


Page 1B-28 90-861328--1 NOVEMBER 1999

EFI1. Connect timing light to number 1 spark plug wire.

2. Start engine and run at 1300 rpm until it reaches normal operating temperature.

3. Stop engine and connect the scan tool or timing tool to the DLC connector on the EFIwiring harness.

4. Start engine, allow rpm to stabilize.

NOTE: MEFI-1 models only, manually adjust remote control throttle lever to get 1200 enginerpm.

NOTE: MEFI-3 models only, ECM will automatically adjust engine rpm to approximately1200 rpm when put in the service mode on a scan tool or when using the timing tool.

5. Check ignition timing. If incorrect, rotate the distributor until timing is correct. Torqueclamping screw to 18 lb-ft (25 Nm).

6. Recheck ignition timing.

7. Disconnect scan tool or timing tool from DLC connector.

8. If required, return remote control throttle lever to idle position and shut off engine.

9. Restart engine, increase rpm to 1300 then return to idle position slowly. Ensure thatengine returns to idle rpm. Readjust throttle cable, if required.

10. Shut engine off.


90-861328--1 NOVEMBER 1999 Page 1B-29

Cold Weather or Extended Storage

Precautions

WARNINGAlways disconnect battery cables from battery BEFORE working on fuel system toprevent fire or explosion.

WARNINGBE CAREFUL while working on fuel system; gasoline is extremely flammable andhighly explosive under certain conditions. Be sure that ignition key is OFF. DO NOTsmoke or allow sources of spark and/or open flames in the area. Wipe up any spilledfuel immediately.

WARNINGAvoid Fire or Explosion: To prevent a potential fire hazard, be sure that engine com-partment is well ventilated and that there are no gasoline vapors present duringstarting or fogging of engine.

WARNINGAvoid Fire or Explosion: Fuel injection system is pressurized during operation. Usecare when removing water separating fuel filter. Fuel could spray on hot enginecausing fire or explosion. Allow engine to cool down before attempting to removethe water separating fuel filter in the following procedure. Also, hold a clean shoptowel over the water separating fuel filter when removing it to help avoid fuel spray-ing on the engine.

CAUTIONIf boat is in the water, seacock (water inlet valve), if equipped, must be closed untilengine is to be restarted, to prevent water from flowing back into cooling systemand/or boat. If boat is not fitted with a seacock, water inlet hose must be discon-nected and plugged to prevent water from flowing back into cooling system and/orboat. As a precautionary measure attach a tag to the ignition switch or steeringwheel of the boat with the warning that the seacock must be opened or the waterinlet hose reconnected prior to starting engine.

CAUTIONDO NOT operate engine without water flowing through seawater pickup pump, aspump impeller may be damaged and subsequent overheating damage to engine orsterndrive unit may result.

CAUTIONIf engine is equipped with Closed Cooling System, Closed Cooling section must bekept filled with a solution of ethylene glycol antifreeze and water (mix antifreeze tomanufacturer’s recommended proportions to protect engine to lowest temperatureto which it will be exposed). DO NOT USE PROPYLENE GLYCOL antifreeze in closedcooling section. Seawater section, however, must be drained completely.

CAUTIONA discharged battery can be damaged by freezing.


Page 1B-30 90-861328--1 NOVEMBER 1999

CAUTIONSeawater section of cooling system MUST BE COMPLETELY drained for winterstorage, or immediately after cold weather use, if the possibility of freezing temper-atures exists. Failure to comply may result in trapped water causing freeze and/orcorrosion damage to engine.

WARNINGWhen running engine with boat out of water, be certain that area in vicinity ofpropeller is clear and that no person is standing nearby. As a precautionarymeasure, it is recommended that the propeller be removed.

CAUTIONDO NOT run engine above 1500 rpm, as suction created by seawater pickup pumpmay collapse water supply hose and cause engine to overheat.

WARNINGBe sure that engine compartment is well ventilated and that no gasoline vapors arepresent to prevent the possibility of a FIRE or EXPLOSION.

IMPORTANT: Observe the following information to ensure complete draining of cool-ing system.• Engine must be as level as possible.

• A wire should be repeatedly inserted into all drain holes to ensure there are noobstructions in passages.

IMPORTANT: To prevent threads in manifolds, elbows and cylinder blocks from rust-ing during storage, reinstall drain plugs. Never leave drain plugs out during storage.

NOTE: If possible, place a container under drains and hoses to prevent water from draininginto boat.


90-861328--1 NOVEMBER 1999 Page 1B-31

Power Package Layup

NOTICE

Refer to “Precautions” in this section BEFORE proceeding.

IMPORTANT: Mercury MerCruiser strongly recommends that this service be per-formed by an Authorized Mercury MerCruiser Dealer. Damage caused by freezing ISNOT covered by the MerCruiser Limited Warranty.

1. Fill fuel tank(s) with fresh gasoline that does not contain alcohol and a sufficient amountof Quicksilver Gasoline Stabilizer for Marine Engines to treat gasoline. Follow instruc-tions on container.

2. If boat is to be placed in storage with fuel containing alcohol in fuel tanks (if fuelwithout alcohol is not available): Fuel tanks should be drained as low as possible andQuicksilver Gasoline Stabilizer for Marine Engines added to any fuel remaining in thetank. Refer to “Fuel Requirements” for additional information.

NOTE: If desired, a portable fuel tank can be used to perform the remainder of the powerpackage layup procedures. Be sure to add an appropriate amount of Gasoline Stabilizer tothe portable tank.

3. Run engine sufficiently to bring it up to normal operating temperature and allow fuel withQuicksilver Gasoline Stabilizer to circulate through fuel system.

4. Shut off engine.

5. Change oil and oil filter.

6. Flush cooling system. Refer to “Flushing Cooling System” procedure.

7. Close the fuel shutoff valve, if equipped. If no fuel shutoff valve is present, a suitablemethod must be employed to STOP the flow of fuel from the fuel tank to the enginebefore proceeding.


Page 1B-32 90-861328--1 NOVEMBER 1999

8. Prepare EFI fuel system for extended storage as follows:

a. Allow engine to cool down.

b. Remove the water separating fuel filter.

c. Pour out a small amount of fuel into a suitable container, then add approximately 2fluid ounces (60 ml) of Quicksilver 2-Cycle Outboard Oil to fuel in the water separat-ing fuel filter.

d. Reinstall water separating fuel filter.

e. Start and operate engine at idle speed until the water separating fuel filter and fuelinjection system are empty and engine stops.

f. Remove and discard water separating fuel filter.

g. Install new filter.

75533a

a - Water Separating Fuel Filter

9. Prepare carbureted fuel system for extended storage as follows:

a. Remove flame arrestor assembly and start engine.

b. While operating engine at fast idle (1000-1500 rpm), fog internal surfaces of induc-tion system and combustion chambers by squirting approximately 8 ounces (227grams) of Quicksilver Storage Seal or SAE 20W engine oil into carburetor bores.

c. Squirt the remaining 2 ounces (57 g) of Storage Seal (or oil) rapidly into carburetor,just as the engine begins to stall due to lack of fuel. Allow engine to stop.

10. Turn ignition key to OFF position.

11. Refer to “Flushing Cooling System” and appropriately remove water supply to the sea-water pickup pump.

12. Clean flame arrestor and crankcase ventilation hoses and reinstall.

13. Lubricate all items listed in “Lubrication” section.

14. Drain seawater section of cooling system as outlined in “Draining Instructions” section.

15. On Models with Closed Cooling System: Test coolant to ensure that it will withstandthe lowest temperature expected during storage.

16. Service batteries per manufacturer’s instructions.

17. Clean outside of engine and repaint any areas required with Quicksilver Primer andSpray Paint. After paint has dried, spray Quicksilver Corrosion and Rust PreventiveType II or wipe down with Quicksilver Storage Seal or SAE 20W engine oil.

18. For sterndrive unit layup, refer to appropriate sterndrive service manual.

NOTE: For additional protection against freezing and rust to the exhaust manifolds andother components, a 50-50 mixture of antifreeze and water can be run through the engineduring Power Package Layup.


90-861328--1 NOVEMBER 1999 Page 1B-33

Draining Instructions

DRAINING SEAWATER (RAW-WATER) COOLED MODELS

NOTICE


IMPORTANT: Engine must be as level as possible to ensure complete draining ofcooling system.

1. Remove drain plugs from bottom of port and starboard manifold fittings.

2. Remove drain plugs (port and starboard) from cylinder block or cylinder block Y-fitting.

CAUTIONAvoid product damage. Do not disturb the Y-fitting when removing the drain plug.There is an ignition control “Knock Sensor” in the upper hole of the fitting. This sen-sor must not be loosened or removed. It is tightened to a critical specification at thefactory.

74073

a

b

cd

e

Starboard Side Shown (Port Similar)a - Exhaust Elbow Drain Plugb - Cylinder Block Drain Plugc - Y-Fitting (Fuel Injected Only)d - Cylinder Block Drain Plug (Fuel Injected Only)e - Knock Sensor


Page 1B-34 90-861328--1 NOVEMBER 1999

3. Repeatedly clean out drain holes using a stiff piece of wire. Do this until entire systemis drained.

NOTE: It may be necessary to lift, bend or lower hoses to allow water to drain completelywhen hoses are disconnected.

4. Remove the engine water circulating pump hose or drain plug, as equipped.

72587

a

76038b

a - Hose, Water Circulating Pump To Thermostat Housingb - Water Circulating Pump Hose Drain Plug

5. Remove the drain plug from the water tube or Cool Fuel System cooler, as equipped.

75081a75018a

Some Carbureted Models Fuel Injected Modelsa - Drain Plug

6. Remove seawater pump inlet hose as shown.

75533a

b

a - Seawater Inlet Hoseb - Hose To Cooler

7. Crank engine over slightly with starter motor to purge any water trapped in seawaterpickup pump. DO NOT ALLOW ENGINE TO START.


90-861328--1 NOVEMBER 1999 Page 1B-35

8. After seawater section of cooling system has been drained completely:

a. Install all drain plugs and tighten securely.

b. Reconnect hoses and tighten all hose clamps securely.

c. If NOT equipped with seacock: Seawater inlet hose must remain disconnectedand plugged until engine is to be restarted.

IMPORTANT: Mercury MerCruiser recommends that propylene glycol antifreeze(nontoxic and biodegradable) be used in seawater section of the cooling system forcold weather or extended storage. Make sure that the propylene glycol antifreezecontains a rust inhibitor and is recommended for use in marine engines. Be certainto follow the propylene glycol manufacturer’s recommendations.

9. For additional assurance against freezing and corrosion in the internal water passages:

a. Remove the thermostat cover and thermostat.

b. Fill the engine seawater cooling system with a mixture of antifreeze and tap watermixed to manufacturer’s recommendation to protect engine to the lowest tempera-ture to which it will be exposed during cold weather or extended storage.

c. Using a new gasket, reinstall thermostat and cover. Tighten cover bolts to 30 lb-ft(41 Nm).

NOTE: Hoses shown removed for visual clarity. Do not remove hoses.

74493

a

b

c

de

a - Housingb - Gasketc - Thermostatd - Spacere - Fill Here


Page 1B-36 90-861328--1 NOVEMBER 1999

DRAINING SEAWATER SECTION OF CLOSED COOLED (COOLANT) MODELS

NOTICE


IMPORTANT: Drain seawater section of closed cooling system only.

IMPORTANT: Engine must be as level as possible to ensure complete draining ofcooling system.

1. Remove drain plug from bottom of port and starboard exhaust manifolds.

74073

a

a - Drain Plug

2. Remove the drain plug from the water tube or Cool Fuel System cooler, as equipped.

75081aa 75018

Some Carbureted Models Fuel Injected Modelsa - Drain Plug

NOTE: It may be necessary to lift, bend or lower hoses to allow water to drain completelywhen hoses are disconnected.


90-861328--1 NOVEMBER 1999 Page 1B-37

3. Remove seawater pump inlet hose.

75533

a

b

a - Seawater Inlet Hoseb - Hose To Cooler

4. Remove end caps, sealing washers and gaskets from the heat exchanger. Allow tubesto drain.

71515

b

c

d

a

a - Heat Exchangerb - Sealing Washerc - End Capd - Gasket

IMPORTANT: Use compressed air to blow any remaining water from the tubes in theheat exchanger.

5. Repeatedly clean out drain holes using a stiff piece of wire. Do this until entire systemis drained.

6. After seawater section of cooling system has been drained completely:

a. Install all drain plugs and tighten securely.

b. Reconnect hoses and tighten all hose clamps securely.

c. Apply Quicksilver Perfect Seal to both sides of new end plate gaskets.

d. Assemble new gaskets, new sealing washers and end plates onto heat exchanger.Torque end plate screws to 36-72 lb-in. (4-8 Nm).

e. If NOT equipped with seacock: Seawater inlet hose must remain disconnectedand plugged until engine is to be restarted.


Page 1B-38 90-861328--1 NOVEMBER 1999

Draining Sterndrive

NOTICE

Predelivery Preparation Instructions Must Be Performed Before Delivering Boat ToThe Product Owner.

1. On Bravo Drive Equipped Models: Insert a small wire (repeatedly) to make sure thatspeedometer pitot tube, anode cavity vent hole and anode cavity drain passage areunobstructed and drained.

71217

c

b

a

d

e

f

Typicala - Speedometer Pitot Tubeb - Anode Cavity Vent Holec - Anode Cavity Drain Passaged - Gear Housing Water Drain Hole (One Each - Port and Starboard)e - Gear Housing Cavity Vent Holef - Gear Housing Cavity Drain Hole

2. On Alpha Drive Equipped Models: Insert a small wire (repeatedly) to make sure thatspeedometer pitot tube, trim tab cavity vent hole and trim tab cavity drain passage areunobstructed and drained.

71216

a

d

b

c

e

f

a - Speedometer Pitot Tubeb - Trim Tab Cavity Vent Holec - Trim Tab Cavity Drain Passaged - Gear Housing Water Drain Hole (One Each - Port and Starboard)e - Gear Housing Cavity Vent Holef - Gear Housing Cavity Drain Hole


90-861328--1 NOVEMBER 1999 Page 1B-39

Recommissioning

NOTICE


1. Ensure that all cooling system hoses are connected and tight.

2. Ensure all petcocks and drain plugs are installed and tight.

3. Inspect serpentine drive belt for condition and proper tension.

4. Perform all lubrication and maintenance specified for completion “Annually” and “Every100 hours or Annually” in maintenance schedule, except items which were performedat time of engine layup.

5. For sterndrive unit recommissioning, refer to appropriate Sterndrive Service Manual.

CAUTIONWhen installing battery (in next step), be sure to connect positive battery cable topositive (+) terminal and negative (grounded) battery cable to negative (–) batteryterminal. If battery cables are reversed, damage to electrical system WILL result.

6. Install fully charged battery. Clean battery cable clamps and terminals to help retardcorrosion.

CAUTIONDO NOT operate engine without cooling water being supplied to seawater pickuppump or water pump impeller will be damaged and subsequent overheatingdamage to engine may result.

7. Start engine and closely observe instrumentation to ensure that all systems are func-tioning properly.

8. Carefully inspect entire engine for fuel, oil, water and exhaust leaks.

9. Check steering system, shift and throttle controls for proper operation.


Page 1B-40 90-861328--1 NOVEMBER 1999


1C

TROUBLESHOOTINGSERVICE MANUAL NUMBER 25

90-861328--1 NOVEMBER 1999 Page 1C-1

IMPORTANT INFORMATIONSection 1C - Troubleshooting

Table of Contents

Precautions 1C-2. . . . . . . . . . . . . . . . . . . . . . . . Used Spark Plug Analysis 1C-3. . . . . . . . . . . .

Normal Condition 1C-3. . . . . . . . . . . . . . . . . Chipped Insulator 1C-3. . . . . . . . . . . . . . . . . Wet Fouling (Oil Deposits) 1C-4. . . . . . . . . Cold Fouling 1C-4. . . . . . . . . . . . . . . . . . . . . Overheating 1C-4. . . . . . . . . . . . . . . . . . . . . High Speed Glazing 1C-5. . . . . . . . . . . . . . . Scavenger Deposits 1C-5. . . . . . . . . . . . . . Pre-Ignition Damage 1C-5. . . . . . . . . . . . . . Reversed Coil Polarity 1C-6. . . . . . . . . . . . . Splashed Deposits 1C-6. . . . . . . . . . . . . . . . Mechanical Damage 1C-6. . . . . . . . . . . . . .

Poor Boat Performance and/or Poor Maneuverability 1C-7. . . . . . . . . . . . . . . . Improper Full Throttle Engine RPM 1C-8. . . .

RPM Too High 1C-8. . . . . . . . . . . . . . . . . . . RPM Too Low 1C-8. . . . . . . . . . . . . . . . . . . .

Engine Cranks Over But Will Not Start Or Starts Hard 1C-9I. . . . . . . . . . . . . . . . . . . . . . mportant Information 1C-9. . . . . . . . . . . . . . . . .

Thunderbolt V Ignition (No Spark) 1C-10. . . Testing Thunderbolt V Ignition System 1C-10Fuel System Rich 1C-11. . . . . . . . . . . . . . . . . Fuel System Lean 1C-11. . . . . . . . . . . . . . . . Miscellaneous 1C-11. . . . . . . . . . . . . . . . . . . .

Engine Will Not Crank Over 1C-12. . . . . . . . . . . Charging System Inoperative 1C-12. . . . . . . . . Noisy Alternator 1C-13. . . . . . . . . . . . . . . . . . . . . Instrumentation Malfunction 1C-13. . . . . . . . . . Radio Noise 1C-13. . . . . . . . . . . . . . . . . . . . . . . .

Poor Fuel Economy 1C-14. . . . . . . . . . . . . . . . . Engine Runs Poorly at Idle 1C-14. . . . . . . . . . . Engine Runs Poorly At High RPM 1C-15. . . . . Engine Acceleration Is Poor 1C-16. . . . . . . . . . Troubleshooting with Vacuum Gauge 1C-16. . Engine Noise 1C-17. . . . . . . . . . . . . . . . . . . . . . .

Important Information 1C-17. . . . . . . . . . . . . Valve Cover Area 1C-17. . . . . . . . . . . . . . . . . Cylinder Area 1C-18. . . . . . . . . . . . . . . . . . . . Camshaft Area 1C-18. . . . . . . . . . . . . . . . . . . Crankshaft Area 1C-19. . . . . . . . . . . . . . . . . . Miscellaneous 1C-20. . . . . . . . . . . . . . . . . . . .

Oil Pressure 1C-21. . . . . . . . . . . . . . . . . . . . . . . . Miscellaneous 1C-21. . . . . . . . . . . . . . . . . . . . Low Oil Pressure 1C-22. . . . . . . . . . . . . . . . . High Oil Pressure 1C-22. . . . . . . . . . . . . . . . .

Excessive Oil Consumption 1C-23. . . . . . . . . . . Water In Engine 1C-24. . . . . . . . . . . . . . . . . . . . .

Important Information 1C-24. . . . . . . . . . . . . Water on Top of Pistons 1C-25. . . . . . . . . . . Water in Crankcase Oil 1C-25. . . . . . . . . . . .

Engine Overheats 1C-26. . . . . . . . . . . . . . . . . . . Mechanical 1C-26. . . . . . . . . . . . . . . . . . . . . .

Engine Overheats 1C-27. . . . . . . . . . . . . . . . . . . Cooling System 1C-27. . . . . . . . . . . . . . . . . . Insufficient Water Flow from Belt Driven Seawater Pickup Pump 1C-28.

Power Steering 1C-29. . . . . . . . . . . . . . . . . . . . . Poor, Erratic or No Assist 1C-29. . . . . . . . . . Noisy Pump 1C-30. . . . . . . . . . . . . . . . . . . . . . Fluid Leaks 1C-30. . . . . . . . . . . . . . . . . . . . . .

TROUBLESHOOTING SERVICE MANUAL NUMBER 25

Page 1C-2 90-861328--1 NOVEMBER 1999

Precautions

WARNINGAlways disconnect battery cables from battery BEFORE working on fuel system toprevent fire or explosion.

WARNINGAvoid gasoline fire or explosion. Improper installation of brass fittings or plugs intofuel pump or fuel filter base can crack casting and/or cause a fuel leak. Followspecific procedures given in this manual for all fuel line connections.

WARNINGMake sure no fuel leaks exist before closing engine hatch.

WARNINGWhen running engine with boat out of water, be certain that area in vicinity ofpropeller is clear and that no person is standing nearby. As a precautionarymeasure, it is recommended that the propeller be removed.

WARNINGBE CAREFUL while working on fuel system; gasoline is extremely flammable andhighly explosive under certain conditions. Be sure that ignition key is OFF. DO NOTsmoke or allow sources of spark and/or open flames in the area. Wipe up any spilledfuel immediately.

WARNINGAvoid Fire or Explosion: Fuel injection system is pressurized during operation. Usecare when removing water separating fuel filter. Fuel could spray on hot enginecausing fire or explosion. Allow engine to cool down before attempting to removethe water separating fuel filter in the following procedure. Also, hold a clean shoptowel over the water separating fuel filter when removing it to help avoid fuel spray-ing on the engine.

WARNINGBe sure that engine compartment is well ventilated and that no gasoline vapors arepresent to prevent the possibility of a FIRE or EXPLOSION.

WARNINGDO NOT leave helm unattended while performing idle speed adjustment.

CAUTIONDO NOT operate engine without water flowing through seawater pickup pump, aspump impeller may be damaged and subsequent overheating damage to engine orsterndrive unit may result.

CAUTIONDO NOT run engine above 1500 rpm, as suction created by seawater pickup pumpmay collapse water supply hose and cause engine to overheat.


90-861328--1 NOVEMBER 1999 Page 1C-3

Used Spark Plug Analysis

Use the following illustrations for determining serviceability of spark plug. Spark plugcondition also can suggest a variety of possible engine malfunctions and, therefore, canindicate needed engine repairs. When old plugs are replaced, replace entire set. Performplug service only on those plugs suitable for additional service, using the followingprocedures:

1. Remove any oil deposits with solvent and dry plugs thoroughly.

2. Open electrode gap wide enough to permit cleaning and filing.

3. Remove combustion deposits from firing end of spark plug with a plug cleaner. Blow offwith compressed air to remove abrasives.

4. File electrode surfaces to restore clean, sharp edges. Again remove filings withcompressed air.

5. Reset gap to specifications by bending only side electrode with proper tool.

Normal ConditionFew deposits are present and probably will be light tan or gray in color. This plug shows thatplug heat range is compatible with engine, and engine is electrically and mechanically ingood running condition. With proper plug servicing (clean, file and re-gap), this plug can bereinstalled with good results.

72420

Chipped InsulatorChipped insulator usually results from careless plug re-gapping. Under certain conditions,severe detonation also can split insulator firing ends. Replace spark plug.

72420


Page 1C-4 90-861328--1 NOVEMBER 1999

Wet Fouling (Oil Deposits)Plug becomes shorted by excessive oil entering combustion chamber, usually in engine withmany hours of operation. Worn piston rings, cylinder walls, valve guides or valve stem sealsare causes of oil entering combustion chamber. Only engine repairs will permanently relieveoil wet fouling.

IMPORTANT: New engines or recently overhauled engines may wet foul plugs beforenormal oil control is achieved with proper break-in procedures. Such fouled plugsmay be serviced (clean, file and re-gap) and reinstalled.

72420

Cold FoulingDry, black deposits indicate rich fuel mixture or weak ignition. Clogged flame arrestor,flooding carburetor, sticky choke or weak ignition components all are probable causes. If,however, only one or two plugs in set are fouled, check for sticking valves or bad ignitionleads. After correcting cause, service (clean, file and re-gap) plugs and reinstall.

72421

OverheatingInsulator is dull white or gray and appears blistered. Electrodes are eroded and there is anabsence of deposits. Check that correct plug heat range is being used. Also check forover-advanced ignition timing, cooling system malfunction, lean fuel/air mixtures, leakingintake manifold or sticking valves. Replace spark plugs.

72421


90-861328--1 NOVEMBER 1999 Page 1C-5

High Speed GlazingInsulator has yellowish, varnish-like color, indicating that temperatures suddenly have risen,usually during hard, fast acceleration under heavy load. Normal deposits do not get achance to blow off. Instead, they melt and form a conductive coating. Replace plugs. Ifcondition recurs, use colder heat range plug and service plugs more frequently.

72421

Scavenger DepositsPowdery white or yellow deposits are built up on shell, insulator and electrodes. This isnormal appearance with certain branded fuels. Accumulation on ground electrodes andshell areas may be unusually heavy, but may be easily chipped off. Plugs may be serviced(clean, file and re-gap) and reinstalled.

72422

Pre-Ignition DamagePre-ignition damage is caused by excessive high temperatures. Center electrode meltsfirst, followed by ground electrode. Normally, insulators are white but may be dirty if plug hasbeen misfiring. Check for correct plug heat range, advanced ignition timing, lean fuelmixture, incorrect fuel used, malfunctioning cooling system, leaking intake manifold or lackof lubrication. Replace spark plugs.

72422


Page 1C-6 90-861328--1 NOVEMBER 1999

Reversed Coil PolarityConcave erosion of ground electrode is an indication of reversed polarity. Center electrodewill show only normal wear. Engine will misfire and idle rough. To correct, reverse primarycoil leads. Replace spark plugs.

72422

Splashed DepositsSpotted deposits, which sometimes occur after long delayed tune-up, accumulate after along period of misfiring. When normal combustion temperatures are restored, uponinstallation of new plugs, deposits loosen from top of piston and head and are thrown againsthot insulator. Plugs may be serviced (clean, file and re-gap) and reinstalled.

72423

Mechanical DamageMechanical damage to spark plug firing end is caused by foreign object in combustionchamber. Because of valve overlap, small objects can travel from one cylinder to another.Check all cylinders, intake manifold and exhaust material to prevent further damage. Re-place spark plugs.

72423

IMPORTANT: When working on engine, spark plug holes and carburetor throatshould be kept covered to prevent foreign objects from entering combustionchamber.


90-861328--1 NOVEMBER 1999 Page 1C-7

Poor Boat Performance and/or Poor Maneuverability

Symptom Cause

A. Improper drive unit trim angle

B. Improper weight distribution

C. Boat is underpowered

Bow too lowD. Permanent or power hook in boat bot-tom

E. False bottom full of water

F. Improperly adjusted anode (afterplanes)

G. Dirty boat bottom (marine growth)

A. Improper drive unit trim angle

B. Propeller pitch too great

C. Dirty boat bottom (marine growth)

D. Poor running engineBow too high E. Improper weight distribution

F. Rocker in boat bottom

G. False bottom full of water

H. Improperly adjusted anode (afterplanes)

A. Drive unit installed too high on transom

B. Dirty or rough boat bottom

C. Damaged propeller; pitch too small;diameter too small

Propeller ventilatingD. Keel located too close to propeller ortoo deep in the water

E. Water pickup or through hull fittingslocated too close to propeller

F. Hook in boat bottom

G. Propeller plugged up with weeds


Page 1C-8 90-861328--1 NOVEMBER 1999

Improper Full Throttle Engine RPM

RPM Too High

Cause Special Information

Propeller Damaged; pitch too low; diameter toosmall; propeller hub slipping.

Boat

Water pickup or through hull fittingsmounted too close to propeller(ventilation); keel located too close topropeller and/or too deep in the water(ventilation). Drive installed too high ontransom; wrong gear ratio.

Operation

Engine coupler slippingUnit trimmed out too far.

RPM Too Low


Propeller Damaged; pitch too great; diameter toogreat.

Boat

Dirty or damaged bottom; permanent orpower hook in bottom; false bottom full ofwater. Drive installed too low on transom;wrong gear ratio.

Operation Unit trimmed in too far.


90-861328--1 NOVEMBER 1999 Page 1C-9

Engine Cranks Over But Will Not Start Or Starts Hard

Important Information1. First, determine which engine system is causing the problem. To make an engine run,

basic components - fuel, spark (ignition), and compression - are required. If all threecomponents are present, the engine should run. If any one of the three are missing,weak, or arriving at the wrong time the engine will not run.

2. Check ignition system operation. Remove coil wire from tower on distributor cap. Holdcoil wire near ground and check for spark while cranking engine over. Repeat procedurewith spark plug wires. If there is spark at the spark plug wires, remove the spark plugsand make sure they are correct type and heat range, and not fouled or burned.

3. Run a compression check on engine to make sure the engine is mechanically OK.

Thunderbolt V Ignition (No Spark)


Moisture on ignition components Distributor cap or spark plug wires arcing

Battery, electrical connections, damagedwiring

Ignition switch

Shift interrupter switch (Alpha One ModelsOnly)

Shorted tachometer Disconnect tachometer and try again

Ignition timing

Spark plugs Fouled, burned, cracked porcelain

Spark plug wires Faulty insulation, broken wires

Cracked or dirty distributor cap

Faulty ignition components Check components

Engine synchronizer (if equipped) hookedup series on purple ignition wire (dualengines only)

Synchronizers must be hooked up directlycoil terminal (parallel chute)


Page 1C-10 90-861328--1 NOVEMBER 1999

Testing Thunderbolt V Ignition System

Ensure that tachometer GRY lead is not shorted toEnsure that tachometer GRY lead is not shorted toground (-) at the tachometer or within the harness.

No Spark

Check all terminal connections at distributor, ignition module and ignition coil.Battery OK?

Distributor clamping screw tight?

No SparkCheck

With key in RUN position, check for 12 volts at

engine andinstrumentWith key in RUN position, check for 12 volts at

positive (+) terminal on ignition coil.0 Volts wiring har-

ness, batterycables, key

switch.

Unplug WHT/RED bullet connector from distributor.0 Volts Check for 12 volts on lead coming from module.

12 Volts

Reconnect WHT/RED bullet connectors. Removehigh-tension lead from distributor to coil. Insert a

spark gap tester from coil tower to ground. Discon-nect WHT/GRN lead from distributor. Place ignitionkey in RUN position. Rapidly strike the terminal of Spark at

Replace igni-key in RUN position. Rapidly strike the terminal of

the WHT/GRN lead that comes from module,Spark at

coil.tion sensor

in distributor.against ground (-).

No spark at coil.

Substitute a new ignition coil. Repeat above Spark at Install newSubstitute a new ignition coil. Repeat abovetest.

Spark atcoil.

Install newignition coil.

No spark at coil.

Replace ignition module.

IMPORTANT: The WHT/GRN lead must be touched against ground (–) 2-3 times persecond to simulate a running engine. Repeat this test several times to ensure thatspark is present.


90-861328--1 NOVEMBER 1999 Page 1C-11

Fuel System Rich


Clogged flame arrestor

Excessive fuel pump pressure

Fuel pressure regulator defective

Fuel System Lean


Empty fuel tank

Fuel shut-off valve closed (if equipped)

Vapor lock Engine will not start after warm engineshut down

Miscellaneous


Low grade or stale fuel

Water in fuel


Page 1C-12 90-861328--1 NOVEMBER 1999

Engine Will Not Crank Over


Remote control lever not in neutral posi-tion

Battery charge low; damaged wiring; looseelectrical connections

Circuit breaker tripped

Blown fuse

Ignition switch

Slave solenoid

Faulty neutral start safety switch Open circuit

Starter solenoid

Starter motor

Mechanical engine malfunction

Charging System Inoperative


Loose or broken serpentine belt

Engine rpm too low on initial start Rev engine to 1500 rpm

Loose or corroded electrical connections

Faulty battery gauge Best way to test is to replace gauge

Battery will not accept charge Low electrolyte or failed battery

Faulty alternator or regulator

Refer to SECTION 4C for complete“Charging System” diagnosis procedures


90-861328--1 NOVEMBER 1999 Page 1C-13

Noisy Alternator


Loose mounting bolts

Drive belt Worn, frayed, loose

Loose drive pulley

Worn or dirty bearings

Faulty diode trio or stator

Instrumentation Malfunction


Faulty wiring, loose or corroded terminals

Faulty key switch Test, as outlined in SECTION 4D

Faulty gauge Test, as outlined in SECTION 4D

Faulty sender Test, as outlined in SECTION 4D

Radio Noise


A “popping” noise that will increase withengine rpm. Noise will stop as soon as en-gine is turned off.

Ignition System - wrong spark plugs;cracked distributor cap; cracked coil tower;leaking spark plug wires; moisture onignition components

“High pitched whine” in the radio Alternator - poor brush contact on the sliprings

A “hissing or crackling” noise when instru-ments are jarred with ignition on

Instrumentation - loose connections, orantennae wire routed too close to instru-ments

Varying unexplained noises

Accessories - bilge pump, bilge blower;fish finder, depth locator; cabin heatermotor, etc. Disconnect one at a time untilnoise disappears.


Page 1C-14 90-861328--1 NOVEMBER 1999

Poor Fuel Economy


Fuel leaks

Operator habits

Prolonged idling; slow acceleration; failureto cut back on throttle once boat is onplane; boat overloaded; uneven weightdistribution

Engine laboringBent, damaged, or wrong propeller. Watertest boat for proper operating rpm at wide-open-throttle

Clogged flame arrestor

Engine compartment sealed too tight Not enough air for engine to run properly

Boat bottom Dirty (marine growth), hook, rocker

Improper fuel

Crankcase ventilation system not working

Engine running too cold or too hot

Plugged or restricted exhaust

Engine Low compression

Engine Runs Poorly at Idle

Symptoms Cause

Engine surges

Low top speed or lack of power Refer to “Fuel Injection System Trouble-Poor cold engine operation

Refer to “Fuel Injection System Trouble-shooting,” SECTION 5H

Engine stalls

Hard starting Refer to “Engine Starts Hard”


90-861328--1 NOVEMBER 1999 Page 1C-15

Engine Runs Poorly At High RPM


Also refer to “Poor Boat Performance”

Crankcase overfilled with oil Check oil level with boat at rest in thewater.

Anti-siphon valve (if equipped) Restricting fuel supply

Plugged fuel tank vent

Fuel supply Refer to “Fuel Injection SystemTroubleshooting,” SECTION 5H

Ignition timing

Low grade of fuel or water in the fuel

Spark plugs Fouled, burned, cracked porcelain,incorrect heat range

Spark plug wires Poor insulation, broken wires

Distributor cap or rotor Dirty or cracked

Coil

Distributor Excessive play in shaft

Engine overheating Refer to “Engine Overheats”

Low compression Worn valves, rings, cylinders, etc.

Restricted exhaust


Page 1C-16 90-861328--1 NOVEMBER 1999

Engine Acceleration Is Poor

Cause Special Instructions

Also refer to “Poor Boat Performance”

Idle mixture screws

Incorrect ignition timing

Incorrect distributor or amplifier advancecurve

Refer to SECTION 4B

Cracked or dirty distributor cap or rotor

Vacuum leak Intake manifold

Spark plugs Fouled, burned; wrong heat range;cracked porcelain

Low compression

Troubleshooting with Vacuum Gauge

Reading Cause

Steady reading between 15-21 inches atidle rpm

Normal

Extremely low reading, but steady at idlerpm

Vacuum leak; incorrect timing;underpowered boat; faulty boat bottom

Fluctuates between high and low at idlerpm

Blown head gasket between two adjacentcylinders

Fluctuates 4 or 5 inches very slowly at idlerpm

Spark plug gap too narrow, valves aresticking

Fluctuates rapidly at idle, steadies as rpmis increased

Valve guides are worn

Continuously fluctuates between low andnormal reading at regular intervals at idlerpm

Burned or leaking valve


90-861328--1 NOVEMBER 1999 Page 1C-17

Engine Noise

Important InformationNo definite rule or test will positively determine source of engine noise; therefore, use thefollowing information only as a general guide to engine noise diagnosis.

1. Use a timing light to determine if noise is timed with engine speed or one-half enginespeed. Noises timed with engine speed are related to crankshaft, rods, pistons, pistonpins and flywheel. Noises timed to one-half engine speed are valve train related.

2. The use of a stethoscope can aid in locating a noise source. However, because noisewill travel to other metal parts not involved in the problem, caution must be exercised.

3. If you believe noise is confined to one particular cylinder, ground spark plug leads, oneat a time. If noise lessens noticeably or disappears, it is isolated to that particularcylinder.

4. Try to isolate the noise to location in engine: front to back, top to bottom. This can helpdetermine which components are at fault.

5. Sometimes noises can be caused by moving parts coming in contact with othercomponents. Examples are: flywheel or coupler; exhaust flappers rattling againstexhaust pipe; crankshaft striking (pan, pan baffle, or dipstick tube); rocker arm strikingvalve cover; and loose flywheel cover. In many cases if this is found to be the problem,a complete engine teardown is not necessary.

6. When noise is isolated to a certain area and component, removal and inspection will berequired. Refer to proper sections of service manual for information required for service.

7. If noise cannot be distinguished between engine and drive unit, remove drive from boat.Run a water supply directly to engine. Run engine without the drive to determine if noiseis still there.

Valve Cover Area

Location Possible Causes

Rocker arm striking valve cover

Valve cover area, timed to one-half engine Rocker arm out of adjustment

speed, noise could be confined to onecylinder or may be found in any multitude

Worn rocker armcylinder or may be found in any multitudeof cylinders Bent push rod

Collapsed lifter


Page 1C-18 90-861328--1 NOVEMBER 1999

Cylinder Area


Sticking valve

Carbon build-up

Connecting rod installed wrong

Cylinder area, may be confined to one Bent connecting rodcylinder or found in more than onecylinder, timed to engine speed Piston

Piston rings

Piston pin

Cylinder worn

Camshaft Area


Crankshaft timing sprocket

Camshaft area, front of engine, timed to Timing chainCamshaft area, front of engine, timed toone half engine speed Valve Lifter

Cam Bearings

Fuel Pump

Camshaft area, center of engine, timed toone half engine speed

Valve Lifterone half engine speed

Cam bearing

Distributor gear

Camshaft area, rear of engine, timed toone half engine speed

Valve lifterone half engine speed

Cam bearings

Loss of oil pressure

Camshaft area, throughout engine, timedto one half engine speed

Valve liftersto one half engine speed

Cam bearings


90-861328--1 NOVEMBER 1999 Page 1C-19

Crankshaft Area


Crankshaft timing sprocket

Crankshaft area, front of engine, timed to Timing chainCrankshaft area, front of engine, timed toengine speed Main bearing

Rod bearing

Crankshaft striking pan or pan baffleCrankshaft area, center of engine, timed Main bearingto engine speed

Rod bearing

Loose flywheel cover

Loose couplerCrankshaft area, rear of engine, timed to Loose flywheelengine speed

Main bearing

Rod bearing

Loss of oil pressureCrankshaft area, throughout engine, timed Main bearingsto engine speed

Rod bearings


Page 1C-20 90-861328--1 NOVEMBER 1999

Miscellaneous

Noise Possible Cause

Advanced timing

Low octane fuelEngine spark knock

Engine running hot

Carbon deposits in engine

Vacuum leak

Leaking exhaust (manifolds or pipes)Hissing

Loose cylinder heads

Blown head gasket

Vacuum leakWhistle

Dry or tight bearing in an accessory

Leaking high tension lead

Sparks jumping Cracked coil tower

Cracked distributor cap

Serpentine drive belt slipping

Squeaks or squeals Dry or tight bearing in an accessory

Parts rubbing together

Rattling in exhaust pipe area Exhaust shutters


90-861328--1 NOVEMBER 1999 Page 1C-21

Oil Pressure

Miscellaneous


Measuring oil pressureUse a good automotive oil pressure testgauge. Do not rely on the oil pressuregauge in the boat.

Check engine oil level with boat at rest inthe water

Oil level should be between the ADD andFULL / OP RANGE / OK marks

Oil level in crankcase above FULL mark

May cause loss of engine rpm, oil pres-sure gauge fluctuation, drop in oil pres-sure, and hydraulic valve lifter noise athigh rpm

Oil level in crankcase below ADD markLow oil pressure; oil pressure gaugefluctuation; internal engine noise and/ordamage

Change in oil pressure

This may be a normal condition. Oilpressure may read high in the cooler timesof the day, and when engine is not up tooperating temperature. As the airtemperature warms up and engine isrunning at normal opening temperature, itis normal for oil pressure to drop.

Low engine oil pressure at idle

With modern engines and engine oils, lowoil pressure readings at idle do notnecessarily mean there is a problem. Ifvalve lifters do not “clatter” (at idle), thereis a sufficient volume of oil to lubricate allinternal moving parts properly. The reasonfor the drop in oil pressure is that engineheat causes an expansion of the internaltolerances in the engine and, also, the oilwill get thin somewhat from heat.

Low engine oil pressure at idle after run-ning at a high rpm

Refer to the two preceding steps

Boats with dual enginesIt is not uncommon to see different oilpressure readings between the twoengines, as long as both engines fall

Boats with dual stations

within specifications. Differences in oilpressure can be attributed to differencesin engine tolerances, gauges, wiring,senders, etc.


Page 1C-22 90-861328--1 NOVEMBER 1999

Low Oil Pressure


Low oil level in crankcase

Defective oil pressure gauge and/orsender

Verify with an automotive test gauge.Refer to SECTION 4D for instrumenttesting.

Thin or diluted oil

Oil broken down; contains water or gas;wrong viscosity; engine running too hot ortoo cold; excessive idling in cold water(condensation)

Oil pump

Relief valve stuck open; pickup tuberestricted; worn parts in oil pump; air leakon suction side of oil pump or pickup oiltube

Oil leak can be internal or external Oil passage plugs leaking, cracked orporous cylinder block

Excessive bearing clearance Cam bearings, main bearings, rodbearings

High Oil Pressure


Oil too thick Wrong viscosity, oil full of sludge or tar

Defective oil pressure gauge and/orsender

Verify with an automotive test gauge

Clogged or restricted oil passage

Oil pump relief valve stuck closed


90-861328--1 NOVEMBER 1999 Page 1C-23

Excessive Oil Consumption


Normal consumption.One quart of oil consumed in 5-15 hoursof operation at wide-open-throttle (espe-cially in a new or rebuilt engine) is normal

Oil leaks Clean bilge, run engine with clean whitepaper on bilge floor, locate oil leak(s)

Oil too thin Oil diluted or wrong viscosity

Oil level too high

Drain holes in cylinder head plugged Oil will flood valve guides

Defective valve seals

Intake manifold gasket leaking

Worn valve stems or valve guides

Defective oil cooler (if equipped) Crack in cooler tubes

Defective piston ringsGlazed, scuffed, worn, stuck, improperlyinstalled; ring grooves worn; improperbreak-in; wrong end gap

Defective cylindersOut of round, scored, tapered, glazed;excessive piston to cylinder clearance;cracked piston

Excessive bearing clearance


Page 1C-24 90-861328--1 NOVEMBER 1999

Water In Engine

Important InformationIMPORTANT: First determine location of water in engine. This information can helpdetermine where the water came from and how it got into the engine. The three mostcommon problems are water on top of pistons, water in crankcase oil or water incrankcase oil and on top of pistons.

After locating water remove all the water from the engine by removing all spark plugs andpumping cylinders out by cranking engine over. Change oil and filter. Replace spark plugs.Start engine and see if problem can be duplicated. If problem can be duplicated, there isa mechanical problem. If the problem cannot be duplicated, the problem is either anoperator error or a problem that exists only under certain environmental conditions.

If water is contained to cylinder(s) only, it is usually entering through the intake system,exhaust system, or head gasket.

If the water is contained to crankcase only, it is usually caused by a cracked or porous block,a flooded bilge or condensation.

If the water is located in both the cylinder(s) and the crankcase, it is usually caused by waterin the cylinders getting past the rings and valves, or complete submersion.

Checking for rust in the intake manifold or exhaust manifolds is a good idea. Rust in theseareas will give clues if the water entered these areas.


90-861328--1 NOVEMBER 1999 Page 1C-25

Water on Top of Pistons


Operator shut engine off at high rpm

Engine “diesels” or tries to run backwards Poor fuel, high idle rpm, timing set toohigh

Rain water running into flame arrestor Hatch cover

Spark plug misfiring Improper combustion causes moisture inthe air to accumulate in the cylinder

Backwash through the exhaust system

Improper engine or exhaust hoseinstallation

Cracked exhaust manifold

Improper manifold to elbow gasket instal-lation

Loose cylinder head bolts

Blown cylinder head gasket Check for warped cylinder head orcylinder block

Cracked valve seat

Porous or cracked casting Check cylinder heads, cylinder block, andintake manifold

Water in Crankcase Oil


Water in boat bilgeBoat has been submerged or bilge waterwas high enough to run in through dipsticktube

Water seeping past piston rings or valves Refer to “Water in Engine” (“On Top of Pis-tons”)

Engine running cold Defective thermostat, missing thermostat;prolonged idling in cold water

Intake manifold leaking near a water pas-sage

Cracked or porous casting Check cylinder head, cylinder block, andintake manifold


Page 1C-26 90-861328--1 NOVEMBER 1999

Engine Overheats

Mechanical


Engine rpm below specifications at wide-open-throttle (engine laboring)

Damaged or wrong propeller; growth onboat bottom; false bottom full of water

Wrong ignition timing Timing too far advanced or retarded

Sticking distributor advance weights

Spark plug wires crossed (wrong firingorder)

Lean fuel mixture

Wrong heat range spark plugs

Exhaust restriction

Valve timing off Jumped timing chain, or improperlyinstalled

Blown head gasket(s)

A blown head gasket(s) normally cannotbe detected by a compression check. Nor-mally the engine will run at normal temper-ature at low rpm, but will overheat atspeeds above 3000 rpm.

Engines that are seawater cooled:Using a clear plastic hose, look for airbubbles between seawater pump andengine. If there are no bubbles present,install clear plastic hose betweenthermostat housing and manifold(s). If airbubbles are present at a higher rpm, it is agood indication there is a blown headgasket.

Insufficient lubrication to moving parts ofengine

Defective oil pump, plugged oil passage,low oil level


90-861328--1 NOVEMBER 1999 Page 1C-27

Engine Overheats

Cooling System


IMPORTANT: The first step is to verify if the engine is actually overheating or thetemperature gauge or sender is faulty.IMPORTANT: Best way to test gauge or sender is to replace them.

Loose or broken drive belt

Seawater shutoff valve partially or fullyclosed (if equipped)

Clogged or improperly installed seastrainer

Loose hose connections between seawa-ter pickup and seawater pump inlet(models with belt driven seawater pumponly)

Pump will suck air. Pump may fail to primeor will force air bubbles into cooling sys-tem.

Seawater inlet hose kinked or collapsed

Seawater pickup clogged

Obstruction on boat bottom causing waterturbulence

Obstruction will be in front of seawaterpickup, causing air bubbles to be forcedinto cooling system

Defective thermostat

Exhaust elbow water outlet holes plugged

Insufficient seawater pump operation Worn pump impeller

Obstruction in cooling system such ascasting flash, sand, rust, salt, etc.

Refer to water flow diagram for enginetype being serviced

Engine circulating pump defective

Also refer to “Engine Overheats -Mechanical”

IMPORTANT: In addition to previous checks, make the following checks if engineis equipped with closed cooling.

Low coolant level

Antifreeze not mixed properlyAntifreeze should be mixed 50/50 ormaximum 60/40 (60% antifreeze, 40%water)

Heat exchanger cores plugged

Water hoses reversed at the waterdistribution block

Refer to water flow diagram in SECTION 6


Page 1C-28 90-861328--1 NOVEMBER 1999

Insufficient Water Flow from Belt Driven Seawater Pickup Pump


Drive belt Loose, worn or broken

Seawater shutoff valve partially or fullyclosed

Clogged or improperly installed seastrainer

Loose hose connections between seawa-ter pickup and seawater pump inlet

Pump will suck air, pump may fail to primeor will force air bubbles into coolingsystem

Seawater inlet hose kinked or plugged

Seawater pickup plugged

Obstruction on boat bottom causing waterturbulence.

Obstruction will be in front of seawaterpickup, causing air bubbles to be forcedinto cooling system

Faulty seawater pump


90-861328--1 NOVEMBER 1999 Page 1C-29

Power Steering

Poor, Erratic or No Assist


Drive belt Worn, broken or out of adjustment

Low fluid level

Air in systemAir leak in lines, pump or air frominstallation. Refer to SECTION 9A forbleeding procedure.

Leaking hoses Refer to SECTION 9A for bleeding proce-dure.

Steering cables and/or steering helmCable or helm partially frozen from rust orcorrosion; cable over-lubricated; impropercable installation.

Binding in sterndrive unit Refer to appropriate Sterndrive ServiceManual

Restriction in hydraulic hoses Causes a loss of pressure

Control valve not positioned properly, notbalanced properly, or the mounting nut isloose

Mounting bracket adjusting screw loose ormounting tube is loose

Faulty pump Flow control valve may be sticking

Worn piston ring or scored housing bore incylinder.

Causes loss of pressure

Leaking valve body or loose fitting spool


Page 1C-30 90-861328--1 NOVEMBER 1999

Noisy Pump


Drive belt Check belt tension

Low fluid level

Air in fluid Air leak in lines, pump or air frominstallation

Faulty pump Use stethoscope to listen for noise inpump

Restricted fluid passages Kinks or debris in hoses or debris inpassages

Stop nut adjusted improperly Refer to appropriate Sterndrive ServiceManual

Steering cables installed that do not meetBIA standards

Refer to appropriate Sterndrive ServiceManual

Fluid Leaks


Loose hose connections Refer to SECTION 9A for bleeding instruc-tions

Damaged hose

Oil leaking from top of pump System overfilled; fluid contains water;fluid contains air

Cylinder piston rod seal

Faulty seals in valve

Faulty seals in o-rings in pump

Cracked or porous metal parts


90-861328--1 NOVEMBER 1999 Page 1C-31



Page 1C-32 90-861328--1 NOVEMBER 1999


2A

MCM MODELSSERVICE MANUAL NUMBER 25

90-861328--1 NOVEMBER 1999 Page 2A-1

REMOVAL AND INSTALLATIONSection 2A - MCM Models

Table of Contents

Torque Specifications 2A-2. . . . . . . . . . . . . . . . Tools 2A-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Lubricants / Sealants / Adhesives 2A-2. . . . . Removal 2A-3. . . . . . . . . . . . . . . . . . . . . . . . . . . Installation and Alignment 2A-5. . . . . . . . . . . .

Engine Connections 2A-10. . . . . . . . . . . . . . Electrical Connections 2A-11. . . . . . . . . . . . . Mercathode Connections 2A-12. . . . . . . . . . Shift Cable Installation 2A-12. . . . . . . . . . . . Power Steering Connections 2A-12. . . . . . . Fuel Supply Connections 2A-13. . . . . . . . . . Throttle Cable Installation and Adjustment 2A-14. . . . . . . . . . . . . . . . . . . . . .

MCM MODELS SERVICE MANUAL NUMBER 25

Page 2A-2 90-861328--1 NOVEMBER 1999

Torque Specifications

Fastener Location lb-in. lb-ft Nm

Cable Barrel Spread Cotter KeyDrive Unit Shift Cable

Cable End Guide See Note

Hose Clamps Securely

Rear Engine Mounts 35-40 47-54

Power Steering Fluid Hose Fitting 23 31

Remote Control Shift Cable Barrel SecurelyRemote Control ShiftCables Cable End Guide See Note

NOTE: Tighten, then loosen nut 1/2 turn.

Tools


Engine Alignment Tool 91-805475A1



Quicksilver Engine Coupler Spline Grease 91-816391A4

Quicksilver Liquid Neoprene 92-27511-2

Loctite 592 Pipe Sealant With Teflon Obtain Locally


90-861328--1 NOVEMBER 1999 Page 2A-3

Removal

IMPORTANT: Sterndrive unit must be removed prior to engine removal. Refer toSterndrive Service Manual.

1. Disconnect battery cables from battery.

2. Remove instrument harness connector plug from engine harness receptacle afterloosening clamp.

WARNINGBe careful when working on fuel system. Gasoline is extremely flammable andhighly explosive under certain conditions. Do not smoke or allow spark or openflame in area. Wipe up any spilled fuel immediately.

3. Using wrench to stabilize brass filter nut at fuel inlet, loosen fuel line fitting. Disconnectand suitably plug fuel line to prevent fuel in tank from leaking into bilge.

4. Disconnect throttle cable from carburetor or throttle body and retain locknuts and hard-ware.

5. Disconnect trim sender bullet connectors from transom assembly from engine harness.

NOTE: After wires are disconnected be sure to loosen them from clamps or sta-strapsretaining them to engine or hoses.

6. Alpha Models: Slide sleeves back on BLK and WHT/GRN or GRY wires and disconnectengine harness wires from shift cut-out switch harness.

7. Disconnect MerCathode wires from MerCathode controller if mounted on engine, ifequipped.

8. Disconnect seawater inlet hose from gimbal housing.

9. Disconnect exhaust elbow hoses (bellows).

10. Remove both shift cables from shift plate. Retain locknuts and hardware.

11. Disconnect any grounding wires and accessories connected to engine.

12. Disconnect and plug fluid hoses from power steering control valve on transom.


Page 2A-4 90-861328--1 NOVEMBER 1999

CAUTIONCenter lifting eye (located on top of thermostat housing) is used for enginealignment only. DO NOT use to lift entire engine.

CAUTIONDO NOT allow lifting sling to hook or compress engine components or damage willoccur.

13. Support engine with suitable sling through lifting eyes on engine and remove front andrear engine mounting bolts. Retain hardware.

75847

a

a

a - Engine Lifting Eyes

14. Carefully remove engine. DO NOT hit power steering control valve.


90-861328--1 NOVEMBER 1999 Page 2A-5

Installation and Alignment

1. Inspect fiber washers (cemented in place) on inner transom plate. Replace if worn ordamaged.

2. Install double wound lockwashers onto inner transom plate inside fiber washer.

3. Ensure that rear engine mount locknuts are in position.

4. Lubricate exhaust bellows with soap and water to ease installation.

5. Lubricate engine coupler splines with Quicksilver Engine Coupler Spline Grease.

72023d

c

b

a

a - Double Wound Lockwasherb - Fiber Wound Lockwasher (Cemented In Place)c - Inner Transom Plate Mount (Engine Support)d - Locknuts (Engine Mounting Bolts)

CAUTIONCenter lifting eye (located on top of thermostat housing) is used for enginealignment only. DO NOT use to lift entire engine.

CAUTIONDO NOT allow lifting sling to hook or compress engine components or damage willoccur.

6. Attach a suitable sling to lifting eyes on engine and adjust so that engine is level whensuspended.

7. Lift engine into position (in boat), using an overhead hoist.

8. Align rear engine mounts with inner transom plate mounts while simultaneously aligningexhaust tubes with exhaust pipe hoses (bellows).


Page 2A-6 90-861328--1 NOVEMBER 1999

IMPORTANT: Engine attaching hardware must be installed in sequence shown.

9. Install both rear engine mounting bolts and hardware as shown. Torque to 37 lb-ft (50Nm).

72535

ab

d

e

f

g

h

c

a - Rear Engine Mounting Boltb - Large Steel Washerc - Metal Spacerd - Rear Engine Mounte - Double Wound Lockwasherf - Fiber Washer (Cemented in Place)g - Inner Transom Plate Mountsh - Locknut (Hidden In This View)

CAUTIONWhen lowering engine into position DO NOT set engine on shift cable. Shift cableouter casing can be crushed causing difficult or improper shifting.

10. Set engine down on stringers and relieve hoist tension. Disconnect sling from enginelifting eyes and switch sling to center lifting eye.

75847

a

b

b

a - Center Lifting Eyeb - Engine Lifting Eyes


90-861328--1 NOVEMBER 1999 Page 2A-7

CAUTIONDO NOT use an alignment tool from another manufacturer. Alignment tools otherthan Quicksilver Alignment Tool 91-805475A1, may cause improper alignment anddamage to gimbal bearing and/or engine coupler.

CAUTIONTo avoid damage to gimbal bearing, engine coupler, or alignment tool:

� DO NOT attempt to force alignment tool!

� DO NOT raise or lower engine with alignment tool inserted (or partially inserted)in gimbal bearing or engine coupler.

CAUTIONAvoid damage to exhaust system. On engines with single piece manifolds, stresscan be placed on the lower exhaust pipe if front of engine is raised too high whileperforming engine alignment procedure. Ensure that engine is not raised higherthan the top of engine mount adjusting stud.

72536

a

bc

d

e

Engine Mounta - Nut and Lockwasherb - Adjustment Nutc - Turn Adjustment Nut in This Direction (Counterclockwise)d - Slotted Hole Toward Front of Enginee - Tab Washer


Page 2A-8 90-861328--1 NOVEMBER 1999

11. Align engine as follows:

a. Attempt to insert solid end of Quicksilver Alignment Tool through gimbal bearing andinto engine coupler splines. If it will not insert easily proceed to following.

b. While observing the above precautions, CAREFULLY raise and lower front ofengine with hoist, as required, until tool will SLIDE FREELY all the way in and outof engine coupler splines.

70013

ab

a - Quicksilver Alignment Tool (91-805475A1)b - Insert This End of Alignment Tool through Gimbal Housing Assembly

72585

a

b c

a - Alignment Tool (91-80547A1)b - Gimbal Bearingc - Engine Coupler

IMPORTANT: Turn both front engine mount adjustment nuts an equal amount indirection required to align engine.

c. Adjust front engine mounts until they rest on boat stringers.

d. Relieve hoist tension entirely and fasten both front mounts to boat stringer usingappropriate hardware (lag bolts or through-bolts, etc.).

e. Recheck alignment with alignment tool. Tool must enter coupler splines freely. If not,readjust front mounts.

f. When alignment is correct, tighten locknut or nut with lockwasher on each mountsecurely.


90-861328--1 NOVEMBER 1999 Page 2A-9

g. Bend tab washer down against flat on adjusting nut.

72536

a

bc

d

e

a - Locknutb - Adjustment Nutc - Turn Adjustment Nut In This Direction (Counterclockwise) To Raise Front Of

Engined - Slotted Hole To Front Of Enginee - Tab Washer

h. Remove alignment tool if not already removed.

12. Tighten all exhaust system hose clamps securely (use two hose clamps on each con-nection):

a. On Engines with Thru-Prop Exhaust:

72537

b

a

a

Thru Prop Exhaust Showna - Hose Clampsb - Exhaust Tube - Long Tube, Port Side - Short Tube, Starboard Side


Page 2A-10 90-861328--1 NOVEMBER 1999

Engine ConnectionsIMPORTANT: When routing all wire harnesses and hoses, be sure they are routed andsecured to avoid coming in contact with hot spots on engine and avoid contact withmoving parts.

1. Connect seawater hose to water tube at gimbal housing with hose clamp. Tighten clampsecurely.

NOTE: For visual clarity the engine is not shown in position.

72590

a

b

c

Bravo Modelsa - Water Inlet Tubeb - Hose Clampc - Seawater Inlet

72614

b

aa

b

c

Alpha Modelsa - Water Inlet Tubeb - Hose Clampc - Seawater Inlet


90-861328--1 NOVEMBER 1999 Page 2A-11

Electrical Connections1. Connect instrument harness to engine harness with hose clamp. Tighten clamp

securely.

2. Connect trim position sender leads from gimbal housing to leads from engine harness.

72582

a

c

b

d

a - BRN/WHT (From Engine Harness)b - BLK (From Engine Harness)c - BLK (From Transom)d - BLK (From Transom Assembly)

IMPORTANT: Do not attach any accessory ground (–) wires to transom plate groundpoint. Accessory ground wires should only be attached to ground stud on engine.

3. Connect any grounding wires or accessories that may have been disconnected.


Page 2A-12 90-861328--1 NOVEMBER 1999

Mercathode Connections (if equipped)1. Connect MerCathode wires to MerCathode controller assembly. Apply a thin coat of

Quicksilver Liquid Neoprene to all connections.

22232a b c d

a - ORG Wire - From Electrode on Transom Assemblyb - RED/PUR Wire - To Positive (+) Battery Terminalc - BLK Wire - From Engine Harnessd - BRN Wire - From Electrode on Transom Assembly

IMPORTANT: Adjust shift cables as outlined in appropriate Sterndrive ServiceManual.

Shift Cable Installation1. Refer to appropriate Sterndrive Service Manual and install and adjust drive unit and

remote control shift cables, using hardware retained.

Power Steering ConnectionsIMPORTANT: After fluid hose installation in the following, bleed power steeringsystem as outlined in SECTION 1B - “Maintenance” or refer to appropriate SterndriveService Manual.

1. Connect power steering fluid hoses to control valve (large fitting first).

CAUTIONRoute hoses exactly as shown below. This will help avoid stress on the hose fittingsand will help avoid kinks in the hose.

IMPORTANT: Make hydraulic connections as quickly as possible to prevent fluidleakage.

IMPORTANT: DO NOT cross-thread or overtighten fittings.

2. Torque both fittings to 23 lb-ft (31 Nm).

73786


90-861328--1 NOVEMBER 1999 Page 2A-13

3. Connect battery cables to battery by FIRST connecting POSITIVE (+) battery cable(usually RED) to POSITIVE (+) battery terminal. Tighten clamp securely. Then, connectNEGATIVE (–) battery cable (usually BLK) to NEGATIVE (–) battery terminal. Tightenclamp securely.

NOTE: Spray terminals with a battery connection sealant to help retard corrosion.

Fuel Supply Connections

WARNINGAvoid gasoline fire or explosion. Improper installation of brass fittings or plugs intofuel pump or fuel filter base can crack casting and/or cause a fuel leak.

� Apply #592 Loctite Pipe Sealant with Teflon to threads of brass fitting or plug.DO NOT USE TEFLON TAPE.

� Thread brass fitting or plug into fuel pump or fuel filter base until finger tight.

� Tighten fitting or plug an additional 1-3/4 to 2-1/4 turns using a wrench. DO NOTOVER TIGHTEN.

� Install fuel line. To prevent over tightening, hold brass fitting with suitablewrench and tighten fuel line connectors securely.

� Check for fuel leaks.

WARNINGBe careful when working on fuel system. Gasoline is extremely flammable andhighly explosive under certain conditions. Do not smoke or allow spark or openflame in area. Wipe up any spilled fuel immediately.

1. Connect fuel line from fuel tank(s) to engine. Tighten connections securely.

2. Check for leaks.


Page 2A-14 90-861328--1 NOVEMBER 1999

Throttle Cable Installation and Adjustment1. Connect throttle cable using hardware retained and adjust as follows:

CARBURETED ENGINES

72013ab

cd d

b

MerCarb 2 Barrel Carburetora - Cable End Guideb - Attaching Hardwarec - Cable Barreld - Anchor Studs

72014

a b

c

d

d

b

b

Weber 4 Barrel Carburetora - Cable End Guideb - Attaching Hardware (DO NOT Overtighten)c - Cable Barreld - Anchor Studs

1. Place remote control handle(s) in neutral, idle position.

IMPORTANT: Be sure that cable is routed in such a way as to avoid sharp bends and/or contact with moving parts. DO NOT fasten any items to throttle cable. Outer cablemust be free to move when cable is actuated.

2. Install cable end guide on throttle lever, then push cable barrel lightly toward throttlelever end. (This will place a slight preload on cable to avoid slack in cable when movingremote control lever.) Adjust barrel on throttle cable to align with anchor stud.

3. Secure throttle cable with hardware (retained). Tighten cable end guide nut until it con-tracts and then loosen 1/2 turn. Tighten cable barrel securely. DO NOT OVERTIGHTEN,as cable must pivot freely.


90-861328--1 NOVEMBER 1999 Page 2A-15

4. Place remote control throttle lever in the wide-open-throttle (WOT) position. Ensure thatthrottle shutters (valves) are completely open and throttle shaft lever contactscarburetor body casting.

5. Return remote control throttle lever to idle position and check to ensure that throttle levercontacts idle speed adjustment screw.

74104

ab

Weber 4 Barrel Carburetor Wide-Open-Throttlea - Throttle Shaft Leverb - Carburetor Body Casting

70392

b

a

Weber 4 Barrel Carburetor Idle Positiona - Throttle Leverb - Idle Speed Adjustment Screw


Page 2A-16 90-861328--1 NOVEMBER 1999

EFI ENGINES

1. Install cable end guide on throttle lever, then push cable barrel end lightly toward throttlelever end. (This will place a slight preload on shift cable to avoid slack in cable whenmoving remote control lever). Adjust barrel on throttle cable to align with hole in anchorplate.

2. Secure throttle cable with hardware as shown and tighten securely. Tighten locknut untilit contacts, then loosen one-half turn.

3. Place remote control throttle level in the wide open throttle (WOT) position. Ensure thatthrottle plates are completely open.

4. Return remote control throttle lever to idle position.

75867

c

d

b

a

a - Cable End Guideb - Flat Washer and Locknutc - Cable Barreld - Flat Washer and Locknut


90-861328--1 NOVEMBER 1999 Page 2A-17



Page 2A-18 90-861328--1 NOVEMBER 1999


3A

262 CID (4.3L) ENGINESSERVICE MANUAL NUMBER 25

90-861328--1 NOVEMBER 1999 Page 3A-1

ENGINESection 3A - 262 cid (4.3L) Engines

Table of ContentsTorque Specifications 3A-2. . . . . . . . . . . . . . . Lubricants / Sealants / Adhesives 3A-4. . . . . Tools 3A-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Specifications 3A-6. . . . . . . . . . . . . . . . . . . . . . . General 3A-11. . . . . . . . . . . . . . . . . . . . . . . . . . . . Bearing Failures 3A-14. . . . . . . . . . . . . . . . . . . . Piston Failures 3A-16. . . . . . . . . . . . . . . . . . . . . .

Pre-Ignition 3A-16. . . . . . . . . . . . . . . . . . . . . . Detonation 3A-17. . . . . . . . . . . . . . . . . . . . . . .

Engine Mounts 3A-19. . . . . . . . . . . . . . . . . . . . . . Rocker Arm Cover 3A-20. . . . . . . . . . . . . . . . . . .


Intake Manifold 3A-21. . . . . . . . . . . . . . . . . . . . . Removal 3A-21. . . . . . . . . . . . . . . . . . . . . . . . Cleaning and Inspection 3A-23. . . . . . . . . . . Installation 3A-24. . . . . . . . . . . . . . . . . . . . . . .

Rocker Arm / Push Rod 3A-27. . . . . . . . . . . . . . Removal 3A-27. . . . . . . . . . . . . . . . . . . . . . . . Cleaning and Inspection 3A-28. . . . . . . . . . . Installation 3A-28. . . . . . . . . . . . . . . . . . . . . . .

Hydraulic Roller Valve Lifters 3A-29. . . . . . . . . Locating Noisy Lifters 3A-30. . . . . . . . . . . . . Removal 3A-31. . . . . . . . . . . . . . . . . . . . . . . . Cleaning and Inspection 3A-34. . . . . . . . . . . Installation 3A-34. . . . . . . . . . . . . . . . . . . . . . .

Valve Stem Oil Seal / Valve Spring 3A-36. . . . Removal - Head Installed 3A-36. . . . . . . . . . Valve Assembly (Exploded View) 3A-38. . . Installation - Head Installed 3A-39. . . . . . . .

Cylinder Head 3A-40. . . . . . . . . . . . . . . . . . . . . . Removal 3A-40. . . . . . . . . . . . . . . . . . . . . . . . Cleaning and Inspection 3A-42. . . . . . . . . . . Installation 3A-43. . . . . . . . . . . . . . . . . . . . . . .

Cylinder Head and Valve Conditioning 3A-47. Disassembly 3A-47. . . . . . . . . . . . . . . . . . . . . Cleaning 3A-47. . . . . . . . . . . . . . . . . . . . . . . . Inspection 3A-48. . . . . . . . . . . . . . . . . . . . . . . Valve Guide Bore Repair 3A-49. . . . . . . . . . Valve Springs - Checking Tension 3A-50. . . Valve Seat Repair 3A-50. . . . . . . . . . . . . . . . Valve Grinding 3A-51. . . . . . . . . . . . . . . . . . . Reassembly 3A-52. . . . . . . . . . . . . . . . . . . . .

Dipstick Specifications 3A-55. . . . . . . . . . . . . . . Oil Pan 3A-56. . . . . . . . . . . . . . . . . . . . . . . . . . . .


Oil Pump 3A-57. . . . . . . . . . . . . . . . . . . . . . . . . . . Removal 3A-57. . . . . . . . . . . . . . . . . . . . . . . . Disassembly 3A-58. . . . . . . . . . . . . . . . . . . . . Cleaning and Inspection 3A-58. . . . . . . . . . . Reassembly 3A-58. . . . . . . . . . . . . . . . . . . . . Installation 3A-59. . . . . . . . . . . . . . . . . . . . . . .

Torsional Damper 3A-59. . . . . . . . . . . . . . . . . . . Removal 3A-59. . . . . . . . . . . . . . . . . . . . . . . . Installation 3A-60. . . . . . . . . . . . . . . . . . . . . . .

Crankcase Front Cover Oil Seal 3A-61. . . . . . . Crankcase Front Cover 3A-62. . . . . . . . . . . . . .

Removal 3A-62. . . . . . . . . . . . . . . . . . . . . . . . Cleaning and Inspection 3A-63. . . . . . . . . . . Installation 3A-63. . . . . . . . . . . . . . . . . . . . . . .

Flywheel 3A-64. . . . . . . . . . . . . . . . . . . . . . . . . . . Removal 3A-64. . . . . . . . . . . . . . . . . . . . . . . . Inspection 3A-64. . . . . . . . . . . . . . . . . . . . . . . Installation 3A-65. . . . . . . . . . . . . . . . . . . . . . .

Rear Main Oil Seal 3A-66. . . . . . . . . . . . . . . . . . Removal 3A-66. . . . . . . . . . . . . . . . . . . . . . . . Cleaning and Inspection 3A-67. . . . . . . . . . . Installation 3A-67. . . . . . . . . . . . . . . . . . . . . . .

Rear Main Oil Seal Retainer 3A-68. . . . . . . . . . Removal 3A-68. . . . . . . . . . . . . . . . . . . . . . . . Cleaning and Inspection 3A-68. . . . . . . . . . . Installation 3A-68. . . . . . . . . . . . . . . . . . . . . . .

Main Bearings 3A-69. . . . . . . . . . . . . . . . . . . . . . Inspection 3A-69. . . . . . . . . . . . . . . . . . . . . . . Replacement 3A-71. . . . . . . . . . . . . . . . . . . . .

Connecting Rod Bearings 3A-74. . . . . . . . . . . . Inspection and Replacement 3A-74. . . . . . .

Connecting Rod / Piston Assembly 3A-76. . . . Removal 3A-76. . . . . . . . . . . . . . . . . . . . . . . . Disassembly 3A-77. . . . . . . . . . . . . . . . . . . . . Cleaning and Inspection 3A-78. . . . . . . . . . . Reassembly 3A-80. . . . . . . . . . . . . . . . . . . . . Installation 3A-82. . . . . . . . . . . . . . . . . . . . . . .

Crankshaft 3A-84. . . . . . . . . . . . . . . . . . . . . . . . . Removal 3A-84. . . . . . . . . . . . . . . . . . . . . . . . Cleaning and Inspection 3A-86. . . . . . . . . . . Installation 3A-87. . . . . . . . . . . . . . . . . . . . . . .

Timing Chain and Sprocket 3A-88. . . . . . . . . . . Removal 3A-88. . . . . . . . . . . . . . . . . . . . . . . . Cleaning and Inspection 3A-88. . . . . . . . . . . Installation - Timing Chain 3A-89. . . . . . . . .

Crankshaft Sprocket 3A-89. . . . . . . . . . . . . . . . . Removal 3A-89. . . . . . . . . . . . . . . . . . . . . . . . Installation 3A-89. . . . . . . . . . . . . . . . . . . . . . . Checking Timing Chain Deflection 3A-90. .

Balance Shaft / Gears 3A-91. . . . . . . . . . . . . . . Removal 3A-91. . . . . . . . . . . . . . . . . . . . . . . . Cleaning and Inspection 3A-93. . . . . . . . . . . Installation 3A-94. . . . . . . . . . . . . . . . . . . . . . .

Camshaft 3A-96. . . . . . . . . . . . . . . . . . . . . . . . . . Measuring Lobe Lift 3A-96. . . . . . . . . . . . . . . Removal 3A-97. . . . . . . . . . . . . . . . . . . . . . . . Inspection 3A-98. . . . . . . . . . . . . . . . . . . . . . . Installation 3A-98. . . . . . . . . . . . . . . . . . . . . . .

Camshaft Bearings 3A-99. . . . . . . . . . . . . . . . . . Removal 3A-99. . . . . . . . . . . . . . . . . . . . . . . . Inspection 3A-100. . . . . . . . . . . . . . . . . . . . . . . Installation 3A-100. . . . . . . . . . . . . . . . . . . . . . .

Cylinder Block 3A-101. . . . . . . . . . . . . . . . . . . . . . Cleaning and Inspection 3A-101. . . . . . . . . . .

Oil Filter By-Pass Valve 3A-105. . . . . . . . . . . . . . Inspection and/or Replacement 3A-105. . . . .

Remote Oil Filter 3A-106. . . . . . . . . . . . . . . . . . . . Inspection and/or Replacement 3A-106. . . . .

262 CID (4.3L) ENGINES SERVICE MANUAL NUMBER 25

Page 3A-2 90-861328--1 NOVEMBER 1999

Torque Specifications 262 cid (4.3L) Engines

Description lb-in. lb-ft Nm

Alternator Brace to Alternator 192 28

Alternator Brace to Engine 30 41

Alternator to Mounting Bracket 35 48

Alternator Mounting Bracket 30 41

Balance Shaft Drive Gear Retaining Stud 120 14

Balance Shaft Driven Gear Bolt(Torque Plus 35°) 15 20

Balance Shaft Thrust Plate 120 14

Camshaft Sprocket 20 27

Camshaft Thrust Plate 106 12

Carburetor 132 15

Connecting Rod Cap Nuts(Torque Plus 70°) 20 27

Coupler/Flywheel 35 48

Crankcase Front Cover 124 14

Crankshaft Pulley Bolt (Cast Aluminum) 40 54

Cylinder Head Bolts - First Sequence

Angle Torque Second Sequence22 30

Angle Torque Second Sequence

Short Bolt 55 DegreesShort Bolt

Medium Bolt 65 Degrees

Long Bolt 75 Degrees

Distributor Hold Down 25 34

Exhaust Manifold 20 27

Flywheel 75 100

Flywheel Housing to Block 30 41

Flywheel Housing Cover 80 9

Front Mount Bracket 30 41

Fuel Filter Bracket Bolt 25 25

Fuel Pump Bracket Bolt 25 25

Fuel Pump Inlet Fitting (Large DiameterSee Note)

96 10.8

Fuel Pump Inlet Fitting (Small DiameterSee Note)

84 9.6

Intake Manifold Bolts 11 15

Knock Sensor 15 20

NOTE: Hold fuel pump using flat surface at outlet before tightening brass fitting.


90-861328--1 NOVEMBER 1999 Page 3A-3

Torque Specifications 262 cid (4.3L) Engines (continued)

Description lb-in lb-ft Nm

Main Bearing Cap 75 100

Oil Filter Adapter Bolts 15 20

Oil Pan Drain Plug 15 20

Oil Pan Screw (1/4-20) 80 9

Oil Pan Nuts (5/16-20) 165 19

Oil Pump 65 68

Oil Pump Cover 80 9

Power Steering Pump Brace to Block 30 41

Power Steering Pump Bracket 30 41

Rear Crankshaft Oil Seal RetainerScrews and Nuts 133 15

Rear Mount (MCM) 40 54

Rocker Arm Cover 106 12

Rocker Arm Nuts 22 30

Roller Lifter Restrictor Plate 12 16

Seawater Pump Brace (if equipped) 30 41

Seawater Pump Bracket (if equipped) 30 41

Spark Plugs 15 20

Starter Motor 50 68

Thermostat Housing 30 41

Torsional Damper 40 54

Water Circulating Pump 30 41

Water Temperature Sender 20 27


Page 3A-4 90-861328--1 NOVEMBER 1999



Quicksilver Loctite 27131 92-809820

Quicksilver RTV Sealer 92-91601-1

Quicksilver Perfect Seal 92-34227--1

Quicksilver Needle Bearing Assembly Lubricant 92-825265A1

General Motors Cam and Lifter Prelube or Equivalent Obtain Locally

Tools

Mercury Marine Special Tools


Piston Ring Expander 91-24697

Engine Coupler Wrench 91-35547

Special Tools

Snap-On Special Tools (see note)


Torque Angle Gauge (Degree Wheel Torquing) TA 360

NOTE: Snap-On Tools can be ordered from your nearest Snap-On branch sales office ordistributor.


90-861328--1 NOVEMBER 1999 Page 3A-5

Kent-Moore Special Tools

Kent-Moore Special Tools29784 Little Mack

Roseville, MI 48066(800) 345-2233


Valve Spring Compressor J5892

Valve Spring Compressor J8062

Valve Spring Tester J8056

Valve Guide Cleaner J8101

Valve Guide Reamer J5830-2

Carbon Remover Brush J8089

Piston Pin Remover Kit J24086-B

Piston Ring Groove Cleaner J3936-03

Piston Ring Compressor J8037

Connecting Rod Bolt Guide Set (3/8-24) J5239

Oil Pump Suction Pipe Installer J21882

Camshaft Bearing Remover and Installer Set J6098-01

Ball Socket Adaptor Tool Kit (Lift Indicator) J8520-1

Torsional Damper Remover and Installer J23523-E

Crankcase Front Cover Seal Installer J35468

Crankshaft Gear and Sprocket Puller J5825-A

Crankshaft Gear and Sprocket Installer J5590

Air Adaptor J23590

Main Bearing Remover/Installer J8080

Rear Main Seal Installer J26817-A

Balance Shaft Rear Bearing Remover J26941

Balance Shaft Bearing Remover/Installer J33834


Page 3A-6 90-861328--1 NOVEMBER 1999

Specifications

262 CID / 4.3L Engine Specifications

NOTICE

Unit Of Measurement: Inches (Millimeters)

Displacement 262 cid (4.3 L)

Bore 4.00 (101.6)

Stroke 3.48 (88.39)

Compression Ratio 9.2:1

Heads Cast Iron

Intake manifold Cast Iron

Block Cast Iron (2 Bolt Main Bearing Caps)

Rods Forged Steel

Pistons Cast Aluminum

Crankshaft Cast Iron

Camshaft Steel

CYLINDER BORE

Diameter 4.0007-4.0017 (101.6178-1016431)

Production .0005 (0.0127) MaximumOut-of-Round

Service .002 (0.05) Maximum

Thrust Side .0005 (0.0127) Maximum

TaperProduction

Relief Side .001 (0.02) Maximum

Service .001 (0.02) Over Production

PISTON

Production .0007-.002 (0.017 - 0.05)Clearance



90-861328--1 NOVEMBER 1999 Page 3A-7


NOTICE


PISTON RING

Top .02-.06 (0.508-1.524)Groove Side Production

2nd .04-.08 (1.016-2.032)Clearance

Service .004 (0.10) MaximumCompression

Top .010-.016 (0.25-0.40)

GapProduction

2nd .018-.026 (0.46-0.66) Maximum

Service .06-.035 (1.52-0.88) Maximum

Groove Side Production .02-.07 (0.508-0.177)Groove SideClearance Service .02-.08 (0.50-2.03) Maximum

OilProduction .015-.050 (0.381-1.27)

GapService .009-.065 (0.23-1.65) Maximum

PISTON PIN

Diameter .9267-.9271 (23.545-23.548)

Production .0002-.0007 (0.0051-0.0177)Clearance in Piston


Fit in Rod .0008-.0016 (0.021-0.040) Interference


Page 3A-8 90-861328--1 NOVEMBER 1999


CRANKSHAFT

NOTICE


No. 1 2.4488-2.4495 (62.199-62.217)

Diameter No. 2, 3 2.4485-2.4494 (62.191-62.215)

No. 4 2.4479-2.4489 (62.179-62.203)

Main Journal Production .0003 (0.007) MaximumTaper


Out-of- Production .0002 (0.005) MaximumOut-of-Round Service .001 (0.02) Maximum

No. 1 .0008-.0020 (0.0203-0.0508)

Main BearingProduction

No. 2, 3, 4 .0011-.0023 (0.0279-0.0584)Main BearingClearance No. 1 .001-.002 (0.03-0.05)

ServiceNo. 2, 3, 4 .001-.002 (0.25-0.06)

Crankshaft End Play .002-.008 (0.05-0.20)

Crankshaft Runout .001 (0.025) Maximum

Diameter 2.2487-2.2497 (57.1170-57.1423)

Production .0003 (0.00508) MaximumConnecting Taper

Service .001 (0.02) MaximumRod Journal

Out-of- Production .0002 (0.007) MaximumOut-of-Round Service .001 (0.02) Maximum

Production .0013-.0035 (0.0330-0.0889)Rod Bearing Clearance

Service .001-.003 (0.02-0.07) Maximum

Rod Side Clearance .006-.017 (0.152-0.44)


90-861328--1 NOVEMBER 1999 Page 3A-9


NOTICE


VALVE SYSTEM

Lifter Hydraulic Roller

Rocker Arm Ratio 1.50:1

Intake .414 (10.52)Valve Lift

Exhaust .428 (10.87)

Valve Lash (Intake and Exhaust) Net Lash No Adjustment

Face Angle (Intake & Exhaust) 45°Seat Angle (Intake & Exhaust) 46°

Seat Runout (Intake & Exhaust) .002 (0.05) Maximum

Intake .035-.060 (0.89-1.52)Seat Width

Exhaust .062-.093 (1.58-2.38)

Intake

StemProduction

Exhaust.0011-.0027 (0.0279-0.069)

StemClearance Intake .001 (0.025) Maximum

ServiceExhaust .002 (0.51) Maximum

IntakeStem Diameter

Exhaust.341 (8.64)

Valve Margin Intake and Exhaust .031 (0.79)

VALVE SPRING

Free Length 2.03 (51.6)

ValveValve

Closed 76-84 Lb. (338-374 N) at 1.7 in (43.16 mm)Spring Pressure

ValveOpen 187-203 Lb. (832-903 N) at 1.27 in (32.25 mm)

Installed Height Intake 1.78 in (45.2 mm)

Installed Height Exhaust 1.69-1.71 in. (42.9-43.43)


Page 3A-10 90-861328--1 NOVEMBER 1999


NOTICE


CAMSHAFT AND DRIVE

±Intake .286-.290 (7.26-7.36)

Lobe Lift ±. 002(0.051)Exhaust .292-.296 (7.42-7.52)

Journal Diameter 1.8682-1.8692 (47.452-47.478)

Journal Out of Round .001 (0.025) Maximum

Camshaft Runout .002 (0.051) Maximum

Camshaft End Play .001-.009 (0..0254-0.2286)

Timing Chain Deflection .375 (9.5) from taut position [total .75 (19)]

FLYWHEEL

Runout .008 (0.203) Maximum

CYLINDER HEAD

Gasket Surface Flatness .010 (0.254) Overall Maximum

BALANCE SHAFT

Front Bearing Journal 2.1648-2.1654 (55.985-55.001)

Rear Bearing Journal 1.4994-1.500 (38.084-38.100)

Rear Bearing InsideDiameter Assembled Production 1.5014-1.503 (37.525-37.575)

Rear Bearing Outside Diameter Production 1.875-1.876 (46.875-46.900)

Rear Cylinder Block Housing Bore Production 1.873-1.874 (46.825-46.850)

Rear Bearing Journal Clearance .001-.0036 (.025-.091)


90-861328--1 NOVEMBER 1999 Page 3A-11

General

Some of the repairs in this section must be completed with engine removed from boat.Engine removal depends upon type of repair and boat design. Place engine on repair standfor major repairs.

When engine removal is not required, make certain that battery cables are disconnectedat the battery prior to performing any on-board engine repair procedure.

Lubricate all moving parts (during reassembly) with engine oil. Apply Quicksilver PerfectSeal on threads of and under heads of cylinder head bolts and on threads of all cylinder blockexternal bolts, screws and studs.

Engine IdentificationThe Mercury MerCruiser Model can be determined by looking at the last two letters of theengine code stamped into the cylinder block. This code number is stamped on all MercuryMerCruiser power packages and replacement partial engines, but not replacement cylinderblock assemblies.

If the engine serial number and/or model decals are missing, the engine code letters mayhelp in determining the engine models.

72873

a

a - Location of GM Engine Code (Front Starboard Side, Near Cylinder HeadMating Surface)

MCM (Sterndrive) Code Rotation

4.3L LJ

4.3LH LK LH

4.3L EFI LK


Page 3A-12 90-861328--1 NOVEMBER 1999

Cylinder Head Identification

72875

4.3

a - Left Hand Rotation (CCW) - All Sterndrive Engines

CrankshaftThe crankshaft is supported in the block by four insert type bearings. Crankshaft end thrustis controlled by flanges on the No. 4 bearing. A torsional damper on the forward end of thecrankshaft serves to help dampen any engine torsional vibration.

Piston and Connecting RodsPiston pins are offset slightly toward the thrust side of the pistons to provide a gradualchange in thrust pressure against the cylinder wall as the piston travels its path. Pins havea floating fit in the piston and a press fit in the connecting rod (to hold them in place).

Connecting rods are made of forged steel and are connected to the crankshaft throughinsert type bearings.

Camshaft and DriveCamshafts are generally cast iron. However, engines with roller lifters have steel camshafts.All camshafts are driven at 1/2 crankshaft speed by a timing chain and sprockets, and aresupported by four main bearings, which are pressed into the block.

A helical gear on the aft end of the camshaft drives the distributor and oil pump.

Balance ShaftThe balance shaft is located in the engine block valley directly above and parallel to thecamshaft. The balance shaft extends the entire length of the engine and is supported oneach end by a bearing. It is also driven by the camshaft through a helical gear set. Thefunction of the balance shaft is to equalize the dynamic forces inherent in particular enginedesigns, thus minimizing engine vibration.


90-861328--1 NOVEMBER 1999 Page 3A-13

Cylinder HeadThe cylinder heads are made of cast iron and have individual intake and exhaust ports foreach cylinder.

Stainless steel or graphite composition head gaskets are used to retard corrosion.

Valve TrainThe valves and valve springs are of a heavy-duty design to withstand the high enginespeeds encountered. Valve tips have been hardened to extend valve life. Exhaust valverotators are used to help extend valve life.

Hydraulic valve roller lifters ride directly on the camshaft lobes and transmit the thrust of thelobes to the push rods which in turn actuate the valves through the rocker arm.

In addition to transmitting thrust of the cam lobes, the hydraulic lifters also serve to removeany clearance (lash) from the valve train to keep all parts in constant contact.

The roller lifters are restrained from rotating by two retainers (restrictors) located in thevalley. The valve lifters also are used to lubricate the valve train bearing surfaces.

Intake ManifoldThe manifold is of the single level design for efficient fuel distribution. All passages are ofapproximately equal length to assure more even fuel-air mixture to the cylinders.

Lubrication SystemThe engine lubrication system is of the force-feed type in which oil is supplied under fullpressure to the crankshaft, connecting rods, camshaft bearings and valve lifters, and issupplied under controlled volume to the push rods and rocker arms. All other moving partsare lubricated by gravity flow or splash.

A positive displacement gear-type oil pump is mounted on the rear main bearing cap andis driven by an extension shaft from the distributor (which is driven by the camshaft). Oil fromthe bottom of the pump in the rear of the oil pan is drawn into the oil pump through an oilpickup screen and pipe assembly.

If the screen should become clogged, a relief valve in the screen will open and continue toallow oil to be drawn into the system. Once the oil reaches the pump, the pump forces theoil through the lubrication system. A spring-loaded relief valve in the pump limits themaximum pump output pressure.

After leaving the pump, the pressurized oil flows through a full-flow oil filter. On engines withan engine oil cooler, the oil also flows through the cooler before returning to the block. Abypass valve allows oil to bypass the filter and oil cooler should they become restricted.

Some of the oil, after leaving the oil cooler and/or filter, is routed to the No. 4 crankshaft mainbearing. The remainder of the oil is routed to the main oil gallery, which is located directlyabove the camshaft and runs the entire length of the block. From the main oil gallery, theoil is routed through individual oil passages to an annular groove in each camshaft bearingbore. Some of the oil is then used to lubricate camshaft bearings. The remainder of the oilis routed to the valve lifter oil galleries and No. 1, 2 and 3 crankshaft main bearings by meansof individual oil passages which intersect with the annular grooves.

The camshaft bearings have holes which align with the oil passages or annular grooves inthe block and allow oil to flow in-between the bearings and the camshaft journals. The oilthat is forced out the front end of the No. 1 camshaft bearing drains down onto the camshaftdrive and keeps it lubricated.


Page 3A-14 90-861328--1 NOVEMBER 1999

The oil which reaches the crankshaft main bearings is forced through a hole in the upperhalf of each bearing and flows in-between the bearings and the crankshaft journals. Someof the oil is then routed to the connecting rod bearings through grooves in the upper half ofthe crankshaft main bearings and oil passages in the crankshaft. Oil which is forced out theends of the connecting rod bearings and crankshaft main bearings is splashed onto thecamshaft, cylinder walls, pistons and piston pins, keeping them lubricated. Oil which isforced out the front end of the No. 1 crankshaft main bearing also assists in lubricating thecamshaft drive.

Oil which reaches the valve lifter oil galleries is forced into each hydraulic valve lifter throughholes in the side of the lifter. From here, the oil is forced through the metering valve in eachof the lifters (which controls the volume of oil flow) and then up through the push rods to therocker arms. A hole in each rocker arm push rod seat allows the oil to pass through therocker arm and lubricate the valve train bearing surfaces. After lubricating the valve train,oil drains back to the oil pan through oil return holes in the cylinder head and block.

The distributor shaft and gear also is lubricated by the oil flowing through the right valve lifteroil gallery.

Bearing Failures

70436a b

Scratched By Dirta - Scratchesb - Dirt Imbedded In Bearing Material

70436

a

Tapered Journala - Overlay Gone From Entire Surface


90-861328--1 NOVEMBER 1999 Page 3A-15

Bearing Failures (Continued)

70436a

Lack Of Oil

a - Overlay Worn Off

70436a

Radius Ridea - Worn Area

70436

a

Improper Seatinga - Bright Or Polished Sections

70436a

Fatigue Failurea - Craters or Pockets


Page 3A-16 90-861328--1 NOVEMBER 1999

Piston Failures

NOTE: Engine failure due to pre ignition or detonation are beyond the control of MercuryMerCruiser. No warranty will apply to failures that occur under these conditions.

Pre-IgnitionPre-ignition is abnormal fuel ignition, caused by combustion chamber hot spots. Control ofthe start of ignition is lost, as combustion pressure rises too early, causing power loss andrough running. The upward motion on the piston is opposed by the pressure rise. This canresult in extensive damage to the internal parts from the high increase in combustionchamber temperature.

72424

Pre-Ignition Damage

72314

a b

c d

Combustion Differencesa - Ignited By Hot Depositsb - Regular Ignition Sparkc - Ignites Remaining Fueld - Flame Front Collide


90-861328--1 NOVEMBER 1999 Page 3A-17

PRE-IGNITION CAUSES

1. Hot spots in the combustion chamber from glowing deposits (due in turn to the use ofimproper oils and/or fuels).

2. Overheated spark plug electrodes (improper heat range or defective plug).

3. Any other protuberance in the combustion chamber, such as an overhanging piece ofgasket, an improperly seated valve or any other inadequately cooled section of materialwhich can serve as a source.

DetonationDetonation, commonly called “fuel knock,” “spark knock” or “carbon knock,” is abnormalcombustion of the fuel which causes the fuel to explode violently. The explosion, in turn,causes overheating or damage to the spark plugs, pistons, valves and, in severe cases,results in pre-ignition.

Use of low octane gasoline is one of the most common causes of detonation. Even with highoctane gasoline, detonation could occur if engine maintenance is neglected.


Page 3A-18 90-861328--1 NOVEMBER 1999

OTHER CAUSES OF DETONATION

IMPORTANT: Use of improper fuels will cause engine damage and poor performance.

1. Over-advanced ignition timing.

2. Lean fuel mixture at or near full throttle (could be caused by carburetor or leaking intakemanifold).

3. Cross-firing spark plugs.

4. Excess accumulation of deposits on piston and/or combustion chamber (results inhigher compression ratio).

5. Inadequate cooling of engine by deterioration of cooling system.

72425

Detonation Damage

72315

a b

c d

Combustion Descriptiona - Spark Occursb - Combustion Beginsc - Combustion Continuesd - Detonation Occurs


90-861328--1 NOVEMBER 1999 Page 3A-19

Engine Mounts

72316

Front Mount

72318

Rear Mount/Flywheel Housing

IMPORTANT: Press rear mount out with press.


Page 3A-20 90-861328--1 NOVEMBER 1999

Rocker Arm Cover

RemovalIt may be necessary to remove exhaust manifold before removing rocker arm cover. (Referto Section 7B)

1. Disconnect crankcase ventilation hoses.

2. Remove any items that interfere with the removal of rocker arm covers.

IMPORTANT: DO NOT pry rocker arm cover loose. Gaskets, which may adhere tocylinder head and rocker arm cover, may be loosened by bumping end of rockercover from the rear with palm of hand or a rubber mallet.

3. Remove rocker arm cover.

Installation1. Clean sealing surfaces on cylinder head and rocker arm cover with degreaser.

2. Place new rocker arm cover gasket in position in rocker arm cover.

75853a

a - Rocker Arm Cover Gasket

3. Install rocker arm cover. Torque screws to 106 lb-in. (12 Nm).

4. Install exhaust manifolds, if removed.

5. Install any items which were removed to allow removal of rocker arm covers.

6. Connect crankcase ventilation hoses to rocker arm covers.

7. Start engine and check for oil leaks.


90-861328--1 NOVEMBER 1999 Page 3A-21

Intake Manifold

Removal1. Drain engine cooling system.

2. Disconnect hoses from thermostat housing.

75847

3. Disconnect electrical leads interfering with removal.

4. Disconnect crankcase ventilation hoses from rocker arm covers.

5. Disconnect throttle cable from carburetor or throttle body.

75867


Page 3A-22 90-861328--1 NOVEMBER 1999

6. Remove fuel line running between fuel pump and carburetor or throttle body.

76404

a

a

a - Fuel Line

7. Remove distributor cap and mark position of rotor on distributor housing. Also, markposition of distributor housing on intake manifold.

8. Remove distributor.

IMPORTANT: Do not crank engine over after distributor has been removed.

9. Remove other ignition components.

10. Remove oil sending unit.

11. Disconnect any other miscellaneous items that will prevent removal of manifold.

IMPORTANT: It may be necessary to pry intake manifold away from cylinder headsand block, in next step. Use extreme care to prevent damage to sealing surfaces.

12. Remove intake manifold bolts, then remove intake manifold and carburetor assembly.

NOTE: If intake manifold requires replacement, transfer all remaining parts to new manifold.


90-861328--1 NOVEMBER 1999 Page 3A-23

Cleaning and Inspection1. Clean gasket material from all mating surfaces.

75853

IMPORTANT: When cleaning cylinder head mating surface, do not allow gasketmaterial to enter engine crankcase or cylinder head ports.

2. Inspect manifold for cracks or scratches. Machined surfaces must be clean and free ofall marks and deep scratches or leaks may result.

3. Check intake passages for varnish buildup and other foreign material. Clean asnecessary.


Page 3A-24 90-861328--1 NOVEMBER 1999

InstallationIMPORTANT: When installing intake manifold gaskets, in next step, observe thefollowing:

• Be sure to install gasket with marked side up. Both gaskets are identical.

• On engines with 2 barrel carburetor, remove metal insert from manifold gasket tobe used on starboard (right) cylinder head to provide clearance for heat pipe onintake manifold.

• All Mercury MerCruiser V-6 GM engines that have “automatic” carburetor chokesmust use an intake gasket that has an opening for the exhaust crossover port inthe intake manifold. Without this opening the “automatic” carburetor choke willnot operate properly. The choke will remain ON longer causing rough engine op-eration and wasted fuel.

71850

a

a - Exhaust Crossover Port Opening

1. Apply Quicksilver Perfect Seal to intake manifold gaskets especially around coolantpassages (both sides).

2. Place gaskets on cylinder heads.

71850

a b a

a - Coolant Passagesb - Gaskets


90-861328--1 NOVEMBER 1999 Page 3A-25

3. Apply a 3/16 in. (5 mm) wide bead of Quicksilver RTV Sealer to engine block as shown.Extend sealer 1/2 in. (13 mm) up on intake gaskets.

IMPORTANT: DO NOT get Quicksilver RTV Sealer into oil sending unit hole at rear ofengine.

71850

a

a

a - RTV Sealer (Typical Both Ends)

71851

b

b - Oil Sending Unit Hole

4. Carefully install manifold assembly and torque bolts to 35 lb-ft (48 Nm) in sequence asshown.

72878

1

23

4 8

6

5

7

a

Intake Manifold Torque Sequencea - Front

5. Connect all electrical leads.


Page 3A-26 90-861328--1 NOVEMBER 1999

6. Connect hoses to thermostat housing.

75847

7. Install fuel line to carburetor and fuel pump.

76404

a

a

a - Fuel Line


90-861328--1 NOVEMBER 1999 Page 3A-27

8. Connect crankcase ventilation hoses to rocker arm covers.

9. Install distributor. Position rotor and housing to align with marks made during removal,then install distributor cap.

10. Install other ignition components and reconnect wires.

11. Coat threads of oil pressure sending unit with Quicksilver Perfect Seal and install.

12. Connect any other items which were disconnected from manifold during removal.

13. Start engine.

14. Adjust ignition timing and carburetor.

15. Check hose connections, gaskets and seals for leaks.

16. Inspect fuel line connections for fuel leaks.

Rocker Arm/Push Rod

RemovalNOTE: When servicing only one cylinder’s rocker arms, bring that cylinder’s piston up toTDC before removing rocker arms. When servicing all rocker arms, bring No. 1 piston upto TDC before removing rocker arms.

1. Remove rocker arm covers.

75853


Page 3A-28 90-861328--1 NOVEMBER 1999

2. Remove rocker arm assemblies and push rods.

75674

IMPORTANT: Place rocker arm assemblies and push rods in a rack for reassemblyin their original locations.

Cleaning and Inspection1. Clean parts with solvent and dry with compressed air.

2. Inspect all contact surfaces for wear. Replace all damaged parts.

InstallationIMPORTANT: When installing rocker arms and rocker arm balls, coat bearingsurfaces of rocker arms and rocker arm balls with engine oil.

1. Install push rods in their original locations. Be sure push rods seat in lifter socket.

2. Install rocker arms, rocker arm balls and rocker arm nuts in their original locations.

3. Torque rocker arm nuts to 22 lb-ft (30 Nm). No valve adjustment is required. Valve lashis automatically set when rocker arm nuts are torqued to specification.


90-861328--1 NOVEMBER 1999 Page 3A-29

Hydraulic Roller Valve Lifters

Hydraulic valve lifters require little attention. Lifters are extremely simple in design.Normally, readjustments are not necessary and servicing requires only that care andcleanliness be exercised in the handling of parts.

72031

��

�

�

�

�

�

�

1 - Push Rod Seat Retainer2 - Push Rod Seat3 - Metering Valve4 - Plunger5 - Check Ball6 - Check Ball Spring7 - Check Ball Retainer8 - Plunger Spring9 - Lifter Body

Valve lifters are retained in position and prevented from rotating by two valve retainers, oneon each side of the engine beneath the intake manifold. Care should be exercised wheninstalling the retainers to see that the flat portions of the lifters are properly positioned intothe retainers.

71853

a

b

a - Retainerb - Roller Lifter Flat Portion


Page 3A-30 90-861328--1 NOVEMBER 1999

Locating Noisy LiftersLocate a noisy valve lifter by using a piece of garden hose approximately 4 ft (1.2 m) inlength. Place one end of hose near end of each intake and exhaust valve, with other endof hose to the ear. In this manner, sound is localized, making it easy to determine which lifteris at fault.

Another method is to place a finger on face of valve spring retainer. If lifter is not functioningproperly, a distinct shock will be felt when valve returns to its seat.

General types of valve lifter noise are as follows:

1. Hard rapping noise - usually caused by plunger becoming tight in bore of lifter body sothat return spring cannot push plunger back up to working position. Probable causesare:

a. Excessive varnish or carbon deposit, causing abnormal stickiness.

b. Galling or “pickup” between plunger and bore of lifter body, usually caused by anabrasive piece of dirt or metal wedged between plunger and lifter body.

2. Moderate rapping noise - probable causes are:

a. Excessively high leakdown rate.

b. Leaky check valve seat.

c. Improper adjustment.

3. General noise throughout valve train - this will, in most cases, be a definite indicationof insufficient oil supply or improper adjustment.

4. Intermittent clicking - probable causes are:

a. A microscopic piece of dirt momentarily caught between ball seat and check valveball.

b. In rare cases, ball itself may be out of round or have a flat spot.

c. Improper adjustment.

In most cases, where noise exists in one or more lifters, all lifter units should be removed,disassembled, cleaned in solvent, reassembled and reinstalled in engine. If dirt, corrosion,carbon, etc., is shown to exist in one unit, it more likely exists in all the units; thus it wouldonly be a matter of time before all lifters caused trouble.


90-861328--1 NOVEMBER 1999 Page 3A-31

Removal1. Remove rocker arm covers.

75853

2. Remove intake manifold.

IMPORTANT: Keep valve push rod and hydraulic lifter from each valve together as amatched set and mark or store them so they can be reinstalled in the same locationlater.


Page 3A-32 90-861328--1 NOVEMBER 1999

3. Remove rocker arm assemblies and push rods.

75670

a

b

a - Rocker Arm Assemblyb - Push Rods

NOTE: Engines with roller lifters have additional valve train components shown below.

72329

b

a

a - Lifter Restrictor Retainerb - Fasteners

72340

a

b

a - Roller Lifter Restrictorb - Roller Lifter

4. Remove lifter restrictors and lifters.


90-861328--1 NOVEMBER 1999 Page 3A-33

5. Remove fasteners from lifter retainers (restrictors) and remove retainers. Do not disturblifters at this time.

71852

a

b

a - Lifter Retainer (Restrictor)b - Fasteners

6. Make matching marks on all retainers and lifters as to location and orientation in bores,to allow reassembly in exact position on camshaft lobes (so that the roller’s bearing androller will roll in the same direction on the same lobe, if reused).

7. Remove valve lifters.

76586

b

71853

a

b

b

c

a - Roller Lifter Retainerb - Roller Lifter(s)c - Matching Marks


Page 3A-34 90-861328--1 NOVEMBER 1999

Cleaning and Inspection1. Thoroughly clean all parts in cleaning solvent and inspect them carefully.

2. If any parts are damaged or worn, entire lifter assembly should be replaced.

3. If outer lifter body wall is scuffed or worn, inspect cylinder block lifter bore.

4. If roller is worn or damaged, inspect camshaft lobe.

5. If push rod seat is scuffed or worn, inspect push rod.

InstallationIMPORTANT: It is recommended that the engine oil be changed and a new oil filter beinstalled whenever servicing valve lifters or camshaft.

IMPORTANT: Before installing roller lifters, coat the roller with engine oil. If new liftersor a new camshaft have been installed, an additive containing EP lube (such asGeneral Motors Cam and Lifter Prelube or equivalent) should be poured overcamshaft lobes before installing lifters.

IMPORTANT: Before installation, coat entire valve lifter with engine oil.

IMPORTANT: DO NOT install used valve lifters if a new camshaft has been installed.

1. Align matching marks made prior to disassembly, and install hydraulic valve lifters andcomponents. Torque roller lifter retainer (restrictor) plate fasteners to 12 lb-ft (16 Nm).


90-861328--1 NOVEMBER 1999 Page 3A-35

NOTE: Components shown removed in left drawing for visual clarity

71853

a

b

b

c

76586

b

a - Roller Lifter Retainerb - Roller Lifter(s)c - Matching Marks

71852

b

a

a - Lifter Retainer (Restrictor)b - Fasteners

2. Install intake manifold.

3. Install push rods. Ensure push rods seat in lifter socket.

4. Install rocker arms and rocker arm nuts. Torque nuts to 22 lb-ft (30 Nm).

5. Install rocker arm cover. Torque fasteners to 106 lb-in. (12 Nm).

6. Start engine and check for leaks.


Page 3A-36 90-861328--1 NOVEMBER 1999

Valve Stem Oil Seal / Valve Spring Replacement

Removal - Head Installed1. Remove rocker arm cover.

75853

2. Remove spark plug of affected cylinder.

3. Remove rocker arm assembly.

75670


90-861328--1 NOVEMBER 1999 Page 3A-37

4. Install air line adaptor tool (J-23590) in spark plug hole and apply compressed air to holdvalves in place.

76572

NOTE: If compressed air is not available, piston may be brought up to TDC and used to keepvalves from falling out of valve guides.

IMPORTANT: Do not turn crankshaft while valve springs, retainers and locks areremoved or valves will fall into cylinder.

5. Using valve spring compressor as shown, compress valve spring and remove valvelocks.

72881

a

b

a - Valve Spring Compressor (J-5892)b - Rocker Arm Nut

6. Slowly release valve spring compressor. Remove cap, retainer or rotator, and valvespring.

IMPORTANT: Keep air pressure in cylinder while springs, caps and valve locks areremoved or valves will fall into cylinder.


Page 3A-38 90-861328--1 NOVEMBER 1999

7. Remove seals from valve stems and valve guide.

72330

a

a - Intake Valve Guide Seal

Valve Assembly (Exploded View)

75843

a

bc

d

e

f

gh

a - Valve Locksb - Retainerc - Rotatord - Cape - Outer Springf - Valve Stem Oil Sealg - Intake Valveh - Exhaust Valve

1. Lubricate valve guides and valve stems with engine oil.

2. Install each valve in the port from which it was removed or to which it was fitted.


90-861328--1 NOVEMBER 1999 Page 3A-39

Installation - Head Installed1. Install valve guide seal (intake valve only) over valve stem and push down until seated

against head.

2. Set valve spring (with damper installed) and cap in place.

3. Place retainer on intake valve and/or rotator on exhaust valve.

76573

4. While compressing valve spring with valve spring compressor, install oil seal in lowergroove of valve stem, making sure seal is not twisted. A light coating of oil will help pre-vent twisting.

5. Install valve locks (Quicksilver Needle Bearing Assembly Lubricant may be used to holdthem in place) and slowly release tool, making sure locks seat properly in upper groovesof valve stem.

72881

a

b

a - Valve Spring Compressor (J-5892)b - Rocker Arm Nut

6. Install push rods and rocker arm assemblies.


Page 3A-40 90-861328--1 NOVEMBER 1999

7. Torque rocker arm nuts to 22 lb-ft (30 Nm).

76569

8. Install rocker arm cover. Torque to 106 lb-in. (12 Nm).

9. Install spark plug torque to 15 lb-ft (20 Nm).

Cylinder Head

Removal1. Drain engine cooling system.

2. Remove exhaust manifolds.

75052

a

One Piece Exhaust Manifold Showna - Exhaust Manifold

3. Remove intake manifold.


90-861328--1 NOVEMBER 1999 Page 3A-41

4. Remove rocker arm covers.

75853

5. Remove rocker arm assemblies and push rods (keep in order for reassembly in theiroriginal locations).

75670

6. Remove any components attached to front or rear of cylinder head.

7. Remove spark plugs.


Page 3A-42 90-861328--1 NOVEMBER 1999

8. Remove head bolts.

76589

CAUTIONThe head gasket may be holding cylinder head to block. Use care when prying offcylinder heads. DO NOT damage gasket surfaces. DO NOT drop cylinder heads.

9. Place cylinder head on wooden blocks to prevent damage to gasket surfaces.

76576

Cleaning and Inspection1. Clean gasket material and sealer from engine block and cylinder heads.

2. Inspect sealing surfaces for deep nicks and scratches.

3. Inspect for corrosion around cooling passages.

4. Clean head bolt threads and engine block bolt hole threads, making sure no dirt, old oilor coolant remain.


90-861328--1 NOVEMBER 1999 Page 3A-43

Installation

CAUTIONWhen using ribbed stainless steel head gaskets, apply a thin coating of QuicksilverPerfect Seal to both sides of gasket. Too much sealer may hold gasket away fromhead or block causing leakage. DO NOT use sealer on graphite composition headgaskets.

1. Place head gasket in position over dowel pins.

76588

2. Carefully set cylinder head in place over dowel pins.

76576


Page 3A-44 90-861328--1 NOVEMBER 1999

3. Coat threads of head bolts with Quicksilver Perfect Seal and install finger-tight.

76589

4. Torque cylinder heads in two steps. First pass, torque all bolts to 22 lb-ft (30 Nm).Second pass is an angle torque sequence as follows:

First PassShort Bolt

Medium BoltLong Bolt

22 lb-ft (30 Nm)

Short Bolt + 55 DegreesSecond Pass Medium Bolt + 65 Degrees

(Angle Torque)Long Bolt + 75 Degrees

72883

a

Cylinder Head Torque Sequencea - Front


90-861328--1 NOVEMBER 1999 Page 3A-45

5. Install push rods, rocker arm assemblies and lifter restrictors in their original positions.

7656876567


7. Install intake manifold.

8. Install rocker arm covers.

75853

9. Install exhaust manifolds.


Page 3A-46 90-861328--1 NOVEMBER 1999

10. Install spark plugs.

76587

11. Install any components removed from front or rear of cylinder heads.

12. Follow procedures below for your model. Refer to SECTION 6A or 6B of this manual.

Seawater Cooled Models: Provide for adequate water supply to seawater pickup (seeSection 6A).

Closed Cooled Models: Refill closed cooling section (see Section 6B), and provide ade-quate water supply to seawater pickup.

CAUTIONEnsure that cooling water supply is available before starting the engine.

13. Start engine.

14. Set timing.

15. Set idle speed.

16. Check for leaks.


90-861328--1 NOVEMBER 1999 Page 3A-47

Cylinder Head and Valve Conditioning

Disassembly1. Using valve spring compressor, compress valve spring and remove valve locks. Slowly

release tool.

72884

a

a - Valve Spring Compressor (J-8062)

2. Remove all valve components.

3. Remove valves from cylinder head and place in a rack, in order, for reassembly in theiroriginal locations.

Cleaning1. Clean push rods and rocker arm assemblies.

2. Clean carbon from valves using a wire wheel.

3. Clean gasket material from cylinder head mating surfaces.

4. Clean all carbon from combustion chambers and valve ports using carbon removerbrush.

72334

a

a - Carbon Remover Brush (J-8089)


Page 3A-48 90-861328--1 NOVEMBER 1999

5. Thoroughly clean valve guides with valve guide cleaner.

72335

a

a - Valve Guide Cleaner (J-8101)

Inspection1. Inspect cylinder heads for cracks in exhaust ports, water jackets, and combustion

chambers (especially around spark plug holes and valve seats). Replace heads if anycracks are found.

2. Inspect cylinder head gasket surface for burrs, nicks, erosion or other damage. Also,check flatness of cylinder head gasket surface, using a machinist’s straight edge andfeeler gauges as shown. Take measurements diagonally across head (both ways) andstraight down center head. Refer to “Specifications.”

72885

a

b

a - Straight Edgeb - Feeler Gauge

IMPORTANT: Cylinder head-to-block gasket surface should be resurfaced if warpedmore than specified. When head resurfacing is required, cylinder head-to-intakemanifold gasket surface on head must be milled to provide proper alignmentbetween intake manifold and head.

3. Inspect valves for burned heads, cracked faces or damaged stems.


90-861328--1 NOVEMBER 1999 Page 3A-49

IMPORTANT: Excessive valve stem to bore clearance will cause excessive oilconsumption and possible valve breakage. Insufficient clearance will result in noisyand sticky valves.

4. Measure valve stem clearance as follows:

a. Attach a dial indicator to cylinder head, positioning it against the valve stem andclose to the valve guide.

b. Holding valve head off seat about 1/16 in. (2 mm), move valve stem back and forthin direction shown. Compare stem clearance with specifications.

c. If clearance exceeds specifications, it will be necessary to ream valve guides foroversized valves, as outlined under “Valve Guide Bore Repair.”

72336

b

a

c

a - Valve Stemb - Dial Indicatorc - Valve Guide

Valve Guide Bore RepairIMPORTANT: Be sure to measure valve stem diameter of both the intake and exhaustvalve, as valve stem diameter may or may not be the same for both valves.

If .015 in. oversize valves are required, ream valve guide bores for oversize valves, asfollows:

1. Measure valve stem diameter of old valve being replaced and select proper size valveguide reamer from chart below.

Standard Valve Stem Diameter Reamer Required for .015 in. Oversize Valve

.341 in. J-5830-2

2. Ream valve guide bores, as shown.

72886

3. Remove the sharp corner created by reamer at top of valve guide.


Page 3A-50 90-861328--1 NOVEMBER 1999

Valve Springs - Checking TensionUsing valve spring tester, as shown, check valve spring tension with dampers removed.Refer to “Specifications.”

IMPORTANT: Springs should be replaced if not within 10 lbs. (44 N) of specifiedtension.

72308

a

b

a - Valve Spring Tester (J-8056)b - Torque Wrench

Valve Seat RepairValve seat reconditioning is very important, since seating of valves must be perfect forengine to deliver maximum power and performance.

Another important factor is valve head cooling. Good contact between each valve and itsseat in head is important to ensure that heat in valve head will be properly dispersed.

Several different types of equipment are available for reseating valve seats. Equipmentmanufacturer’s recommendations should be followed carefully to attain proper results.

50668

ab c

d

Typical “3-Angle” Valve Seata - Top Angle (30°)b - Seat Angle (46°)c - Bottom Angle (60°)d - Seat Width


90-861328--1 NOVEMBER 1999 Page 3A-51

Regardless of type of equipment, however, it is essential that valve guide bores be free fromcarbon or dirt to achieve proper centering of pilot in valve guide, ensuring concentricity.

72338

Measuring Valve Seat Concentricity

Valve GrindingValves that are pitted must be refaced to the proper angle. Valve stems which showexcessive wear, or valves that are warped excessively, must be replaced. When a valvehead which is warped excessively is refaced, a knife edge will be ground on part or all ofthe valve head, due to the amount of metal that must be removed to completely reface. Knifeedges lead to breakage, burning, or pre-ignition due to heat localizing on this knife edge.If the edge of the valve head is less than 1/32 in. (0.8 mm) after grinding, replace the valve.

Several different types of equipment are available for refacing valves. The recommendationof the manufacturer of the equipment being used should be carefully followed to attainproper results.

50695

a

b

a - 1/3 [.341 in] (8.16 mm)b - 1/32 [.031 in] (0.79 mm) Min


Page 3A-52 90-861328--1 NOVEMBER 1999

Reassembly1. Lubricate valve guides and valve stems with engine oil.

2. Install each valve in the port from which it was removed or to which it was fitted.

3. Install valve guide seal (intake valve only) over valve stem and push down until seatedagainst head.

4. Install quad ring over exhaust valve stem until it touches cylinder head with valve closed.

IMPORTANT: The exhaust valve guide seals have been removed. They are replacedwith a quad ring as shown below. If repairing heads with seals, replace them with thequad ring upon reassembly.

75307a

b

a - Quad Ringb - Valve Seal

5. Set valve spring (with damper installed) and cap in place.

6. Place retainer on intake valve and/or rotator on exhaust valve.

7. While compressing valve spring with valve spring compressor, install oil seal in lowergroove of valve stem, making sure seal is not twisted. A light coating of oil will helpprevent twisting.

72884

a

a - Valve Spring Compressor (J-8062)


90-861328--1 NOVEMBER 1999 Page 3A-53

8. Install valve locks (Quicksilver Needle Bearing Assembly lube may be used to hold themin place) and slowly release tool, making sure locks seat properly in upper grooves ofvalve stem.

76573

ab

e

75843

a

bc

d

e

f

gh

a - Valve Locksb - Retainerc - Rotatord - Cape - Valve Stem Oil Sealf - Outer Springg - Intake Valveh - Exhaust Valve


Page 3A-54 90-861328--1 NOVEMBER 1999

9. Check installed height of valve springs using a narrow, thin scale. Measure from springseat to top of valve spring, as shown. If measurement exceeds specified height, installa valve spring shim and recheck. DO NOT shim valve springs to give an installed heightless than the minimum specified.

05037

72339

b

a

a - Valve Spring Installed Heightb - Cut Away Scale (Grind Out This Portion)


90-861328--1 NOVEMBER 1999 Page 3A-55

Dipstick Specifications

All Engines

75851

FULL

ADD

23-11/16

27-7/16

1-1/16

13/16

ADD

OP. RANGE

34-13/16 (884)

27-1/2 (699)

1-1/8 (29)

76497


Page 3A-56 90-861328--1 NOVEMBER 1999

Oil PanRemoval

1. Drain crankcase oil.

2. Remove dipstick and tube.

3. Remove oil pan.

Installation1. Clean sealing surfaces of engine block and oil pan.

2. Apply a small amount of Quicksilver RTV Sealer to joints of rear seal retainer and jointsof front cover.

IMPORTANT: Quicksilver RTV Sealer sets up in about 15 minutes. Be sure tocomplete assembly promptly.

72888

b

a

a - Joints of Rear Seal Retainerb - Joints of Front Cover

3. Install oil pan gasket in position.

NOTE: A one-piece oil pan gasket may be reused if it is still pliable and is not cracked, tornor otherwise damaged.

72889

a

a - Oil Pan Gasket

4. Install oil pan. Starting from the center and working outward in each direction, torquenuts and bolts to 18 lb-ft (25 Nm).

5. Install dipstick tube and dipstick.

6. Fill crankcase with required quantity of oil of specified viscosity. Refer to SECTION 1B- “Maintenance.”


90-861328--1 NOVEMBER 1999 Page 3A-57

Oil Pump

72145

�

��

��

�

�

�

�

�

�

�

�

Oil Pump Assembly1 - Extension Shaft2 - Shaft Coupling3 - Pump Body4 - Drive Gear and Shaft5 - Idler Gear6 - Pickup Screen and Pipe7 - Pump Cover8 - Pressure Regulator Valve9 - Pressure Regulator Spring

10 - Plug11 - Retaining Pin12 - Screws

The oil pump consists of two gears and a pressure regulator valve enclosed in a two-piecehousing. Oil pump is driven by distributor shaft which is driven by a helical gear on camshaft.

Removal1. Remove oil pan.

2. Remove gasket carefully, the one-piece gasket for the oil pan may be reused if still pli-able and not cracked, torn or damaged.

72889a

b

a - Oil Pumpb - Pickup Screen and Pipe

3. Remove oil pump.


Page 3A-58 90-861328--1 NOVEMBER 1999

Disassembly1. Remove pump cover.

IMPORTANT: Mark gear teeth for reassembly with same teeth indexing.

2. Remove idler gear and drive gear from pump body.

3. Remove retaining pin, spring, and pressure regulator valve from pump cover.

IMPORTANT: Do not remove pickup screen and pipe assembly, unless replacementis necessary. Loss of press fit condition could result in an air leak and loss of oilpressure.

IMPORTANT: Do not disturb pickup screen on pipe. This is serviced as an assembly.

4. If pickup screen and pipe assembly requires replacement, mount pump in a soft-jawedvise and extract pipe from pump.

Cleaning and Inspection1. Wash all parts in cleaning solvent and dry with compressed air.

2. Inspect pump body and cover for cracks or excessive wear.

3. Inspect pump gears for damage and excessive wear.

4. Check for loose drive gear shaft in pump body.

5. Inspect inside of pump cover for wear that would permit oil to leak past ends of gears.

6. Inspect pickup screen and pipe assembly for damage to screen and pipe.

7. Check pressure regulator valve for fit.

IMPORTANT: Pump gears and body are not serviced separately. If pump gears orbody are damaged or worn, replacement of entire oil pump assembly is necessary.

Reassembly

CAUTIONBe careful of twisting, shearing or collapsing pipe while installing in pump. Pickupscreen must be parallel to oil pan bottom when oil pump is installed.

If pickup screen and pipe assembly was removed, mount pump in a soft-jawed vise, applyQuicksilver Perfect Seal to end of new pipe and, using oil pump suction pipe installer(J-21882), tap the pipe in place with a hammer.

IMPORTANT: Oil internal parts liberally before installation.

1. Install pressure regulator valve and related parts.

2. Install drive gear in pump body.

3. Install idler gear in pump body with smooth side of gear toward pump cover opening.Align marks made in disassembly.

4. Fill gear cavity with engine oil.

5. Install pump cover and torque attaching bolts to 106 lb-in. (12 Nm).

6. Turn extension shaft by hand to check for smooth operation.


90-861328--1 NOVEMBER 1999 Page 3A-59

Installation1. Install pump, with extension shaft, to rear main bearing, aligning extension shaft with

distributor drive shaft.

2. Tighten oil pump bolt to 65 lb-ft (88 Nm).

72889a

b

a - Oil Pumpb - Pickup Screen and Pipe

3. Install oil pan. The one-piece oil pan gasket may be reused if still pliable and not dam-aged.

Torsional Damper

Removal1. Remove drive belt.

2. Remove drive pulley, then remove torsional damper retaining bolt.

IMPORTANT: Do not use a universal claw type puller to remove torsional damper (innext step) as outside ring of torsional damper is bonded in rubber to the hub and useof claw type puller may break the bond.

3. Remove torsional damper with torsional damper remover and installer.

72890

a

a - Torsional Damper Remover and Installer (J-23523-E)


Page 3A-60 90-861328--1 NOVEMBER 1999

InstallationIMPORTANT: The inertia weight section of torsional damper is assembled to the hubwith a rubber type material. The installation procedure (with proper tool) must befollowed or movement of the inertia weight on the hub will destroy the tuning of thetorsional damper.

1. Replace key in crankshaft if it is damaged.

2. Coat seal surface of torsional damper with engine oil.

3. Install torsional damper on crankshaft, using torsional damper remover and installer asfollows:

b. Install appropriate end of threaded rod into crankshaft.

IMPORTANT: Be sure to install threaded rod in crankshaft at least 1/2 in. (13 mm) toprevent damage to threads.

c. Install plate, thrust bearing, washer and nut on rod.

d. Install torsional damper on crankshaft by turning nut until it contracts.

72346

a

a - Torsional Damper Remover and Installer (J-23523-E)

b. Remove tool from crankshaft.

c. To prevent oil leakage, apply Quicksilver RTV sealant to torsional damper keyway.

d. Install torsional damper bolt. Torque to 74 lb-ft (100 Nm).

4. Install drive pulley(s). Torque bolts to 35 lb-ft (48 Nm).

5. Install and adjust drive belt.


90-861328--1 NOVEMBER 1999 Page 3A-61

Crankcase Front Cover Oil Seal

Oil Seal Replacement (Without Removing Front Cover)

REMOVAL

1. Remove torsional damper.

2. Pry seal out of cover from the front with a large screwdriver, being careful not to distortfront cover or damage crankshaft.

INSTALLATION

IMPORTANT: Correct rotation oil seal must be used to prevent oil leak.

73123

b

a

Front Seal WITHOUT Helical Groovesa - Can Be Used on Any Rotation Engineb - Seal Lip Toward Inside of Engine

73124

c ab

Front Seals WITH Helical Groovesa - MCM (LH) Rotation Enginesb - Seal Lip Toward Inside of Enginec - Rotation of Crankshaft as Viewed from Front End Looking Toward Flywheel

End


Page 3A-62 90-861328--1 NOVEMBER 1999

1. Apply Quicksilver Perfect Seal to seal retainer mating surface and apply grease to seallips.

2. Install new seal with open end of seal inward, using crankcase front cover seal installer.Drive seal in until it just contracts. Do not use excessive force.

72347a

a - Crankcase Front Cover Seal Installer (J-35468)

3. Reinstall torsional damper.

Crankcase Front Cover

Removal1. Remove engine from boat if necessary to gain access to cover.

2. Remove torsional damper and oil pan.

3. Remove water circulating pump.

IMPORTANT: Crankcase front cover is not reusable per G.M. Specification. It must bereplaced if removed.

4. Remove crankcase front cover.

76577

5. Drive oil seal out of front cover (from the rear) using a punch.


90-861328--1 NOVEMBER 1999 Page 3A-63

Cleaning and Inspection1. Clean old gasket material and sealer from mating surface on cylinder block.

2. Surfaces must be clean and flat or oil leakage may result.

InstallationIMPORTANT: Crankcase front cover is not reusable per G.M. Specification. It must bereplaced if removed.

1. Install oil seal in cover with lip of seal toward inside of engine, using crankcase frontcover seal installer. To prevent distortion support cover around seal area with anappropriate tool as shown.

72348

b

a

a - Crankcase Front Cover Seal Installer (J-35468)b - Support

2. Coat both sides of front cover gasket with Quicksilver Perfect Seal and place in positionon engine.

3. Install front cover, making sure holes in cover align with dowel pins in block. Torque frontcover attaching screws to 100 lb-in. (11 Nm).

76577

4. Install oil pan and torsional damper.

5. Install water circulating pump.

6. Install engine in boat.

7. Fill crankcase with engine oil.


Page 3A-64 90-861328--1 NOVEMBER 1999

8. Follow procedures in SECTION 6A or 6B of this manual:

Seawater Cooled Models: Provide for adequate water supply to seawater pickup (Referto SECTION 6A).

Closed Cooled Models: Refill closed cooling section (Refer to SECTION 6B), and provideadequate water supply to seawater pickup.

CAUTIONEnsure that cooling water supply is available before starting the engine.

9. Start engine and check for water and oil leaks.

Flywheel

Removal1. Remove engine from boat. Refer to SECTION 2 - “Removal and Installation”.

2. Refer to “Flywheel Housing” description in this section and remove flywheel housing andrelated parts.

3. Remove coupler.

4. Remove flywheel.

72349

Alpha One Coupler

72350

Bravo Coupler

Inspection1. Inspect splines in coupler for wear.

2. Check flywheel ring gear for worn and missing teeth.


90-861328--1 NOVEMBER 1999 Page 3A-65

Installation1. Clean mating surfaces of flywheel and crankshaft. Remove any burrs. Mating surfaces

must be clean bare metal.

2. Aligning dowel hole in flywheel with dowel in crankshaft, install flywheel. Torque boltsto 75 lb-ft (100 Nm).

3. Check flywheel runout as follows:

a. Attach a dial indicator to engine block.

b. Take readings around outer edge of flywheel. Push in on flywheel as far as it will goto remove crankshaft end play.

c. Maximum runout - .008 in. (0.203 mm).

72353

a

a - .008 In. (0.203 mm) Max Runout

IMPORTANT: Insert three rubber bumpers in Alpha coupler before installation onflywheel.

72354

a

a - Rubber Bumper

4. Install drive coupler. Torque bolts to 35 lb-ft (48 Nm).

5. Install flywheel housing and related parts. Torque bolts to 30 lb-ft (41 Nm).

6. Install flywheel housing cover. Torque bolts to 80 lb-in. (9 Nm).

7. Refer to SECTION 2 “Removal and Installation” and install engine.


Page 3A-66 90-861328--1 NOVEMBER 1999

Rear Main Oil Seal

The rear crankshaft oil seal can be replaced without removing the oil pan or rear mainbearing cap from engine.

RemovalRemove seal by using a screwdriver to pry it out of retainer as shown.

72355

c

a

b

a - Rear Sealb - Seal Retainerc - Slots (Three)


90-861328--1 NOVEMBER 1999 Page 3A-67

Cleaning and InspectionClean crankshaft/seal running surface and seal retainer.

IMPORTANT: Correct rotation oil seal must be used to prevent oil leak.

73126

b

a

Rear Seal WITHOUT Helical Groovesa - Can Be Used On Any Rotation Engineb - Seal Lip Toward Inside Of Engine

73127

c

b

a

Rear Seal WITH Helical Groovesa - MCM (LH) Rotation Enginesb - Seal Lip Toward Inside Of Enginec - Rotation Of Crankshaft As Viewed From Flywheel End Looking Forward

Installation1. Apply Quicksilver Perfect Seal to seal retainer mating surface. Apply grease to seal lips.

2. Install seal using rear main seal installer. (J-26817-A)

72356a

a - Rear Main Seal Installer


Page 3A-68 90-861328--1 NOVEMBER 1999

Rear Main Oil Seal Retainer

Removal1. Remove oil pan.

2. Remove oil seal retainer fasteners.

3. Remove oil seal retainer.

72464a

b

a

a - Fastenersb - Oil Seal Retainer

Cleaning and Inspection1. Clean gasket material from mating surfaces.

2. Inspect oil seal retainer for cracks or scored surface.

3. Inspect oil seal for worn, dry or torn rubber. Replace if necessary, refer to “Rear MainOil Seal.”

4. Inspect alignment pin for damage; replace if necessary.

Installation1. Coat seal lips with clean 30W motor oil.

2. Install gasket and oil seal retainer with rear main seal.

3. Coat threads of oil seal retainer fasteners with Loctite Pipe Sealant with Teflon.

4. Install fasteners and torque to 133 lb-in.(15 Nm).

5. Install oil pan fasteners. Torque engine oil pan nuts and bolts 18 lb-ft (25 Nm).

NOTE: A one-piece oil pan gasket may be reused if it is still pliable and is not damaged.


90-861328--1 NOVEMBER 1999 Page 3A-69

Main Bearings

IMPORTANT: Before removing main bearing caps or connecting rod caps, mark themfor reassembly in their original locations.

Main bearings are of the precision insert type and do not use shims for adjustment. Ifclearances are found to be excessive, a new bearing, both upper and lower halves, will berequired. Service bearings are available in standard size and .001 in., .010 in. and .020 in.undersize.

Selective fitting of both rod and main bearing inserts is necessary in production in order toobtain close tolerances. For this reason you may find one half of a standard insert with onehalf of a .001 in. undersize insert which will decrease the clearance .0005 in. from using afull standard bearing.

IMPORTANT: If crankshaft has an undersize journal and a new bearing is required,journal must be reconditioned to accept a .010 or .020 in. undersize bearing as .009in. undersize bearings are not available for service.

InspectionIn general, the lower half of the bearing (except No. 1 bearing) shows a greater wear andthe most distress from fatigue. If, upon inspection, the lower half is suitable for use, it canbe assumed that the upper half is also satisfactory. If the lower half shows evidence of wearor damage, both upper and lower halves should be replaced. Never replace one half withoutreplacing the other half.

Checking ClearancesTo obtain accurate measurements while using Plastigage, or its equivalent, engine must beout of the boat and upside down so crankshaft will rest on the upper bearings and total clear-ance can be measured between lower bearing and journal.

To ensure the proper seating of the crankshaft, all bearing cap bolts should be at theirspecified torque. In addition, before to checking fit of bearings, the surface of the crankshaftjournal and bearing should be wiped clean of oil.

1. With the oil pan and oil pump removed, remove bearing cap and wipe oil from journaland bearing cap to be inspected.

2. Place a piece of gauging plastic the full width of the bearing (parallel to the crankshaft)on the journal as shown.

72357

a

b

a - Gauging Plasticb - Journal


Page 3A-70 90-861328--1 NOVEMBER 1999

3. Install the bearing cap and evenly torque the retaining bolts to specifications. Bearingcap MUST be torqued to specification in order to assure proper reading. Variations intorque affect the compression of the plastic gauge.

IMPORTANT: Do not rotate the crankshaft while the gauging plastic is between thebearing and journal.

4. Remove bearing cap. The flattened gauging plastic will be found adhering to either thebearing cap or journal.

5. On the edge of the gauging plastic envelope there is a graduated scale correlated inthousandths of an inch. Without removing the gauging plastic, measure its compressedwidth (at the widest point) with the graduations on the gauging plastic envelope.

72358

a b

a - Compressed Gauging Plasticb - Graduated Scale

NOTE: Normally main bearing journals wear evenly and are not out of round. However, ifa bearing is being fitted to an out-of-round journal (.001 in. max.), be sure to fit to themaximum diameter of the journal: If the bearing is fitted to the minimum diameter, and thejournal is out of round .001 in., interference between the bearing and journal will result inrapid bearing failure. If the flattened gauging plastic tapers toward the middle or ends, thereis a difference in clearance indicating taper, low spot or other irregularity of the bearing orjournal. Be sure to measure the journal with a micrometer if the flattened gauging plasticindicates more than .001 in. difference.

6. If the bearing clearance is within specifications, the bearing insert is satisfactory. If theclearance is not within specifications, replace the insert. Always replace both upper andlower inserts as a unit.

7. A standard, or .001 in., undersize bearing may produce the proper clearance. If not, itwill be necessary to regrind the crankshaft journal for use with the next undersizebearing.

c. After selecting new bearing, recheck clearance.

8. Proceed to the next bearing. After all bearings have been checked, rotate the crankshaftto see that there is no excessive drag. When checking No. 1 main bearing, loosenaccessory drive belts to prevent tapered reading with plastic gauge.


90-861328--1 NOVEMBER 1999 Page 3A-71

9. Measure crankshaft end play by forcing the crankshaft to the extreme front position.Measure at the front end of the rear main bearing with a feeler gauge as shown[Specifications - .002-.006 (0.06-0.15)].

72360

a

a - Force Crankshaft to Extreme Forward Position

ReplacementNOTE: Main bearings may be replaced with or without removing crankshaft.

72359

ab

c

Main Bearing Insertsa - Lower Bearing Insert (Install in Cap)b - Upper Bearing Insert (Install in Block)c - Oil Groove


Page 3A-72 90-861328--1 NOVEMBER 1999

WITH CRANKSHAFT REMOVED

1. Remove and inspect the crankshaft.

76580

2. Remove the main bearings from the cylinder block and main bearing caps.

76582

3. Coat bearing surfaces of new, correct size, main bearings with oil and install in thecylinder block and main bearing caps.


90-861328--1 NOVEMBER 1999 Page 3A-73

4. Install the crankshaft.

76579

WITHOUT CRANKSHAFT REMOVED

1. With oil pan, oil pump and spark plugs removed, remove cap on main bearing requiringreplacement and remove bearing from cap.

2. Install main bearing remover/installer in oil hole in crankshaft journal. If such a tool is notavailable, a cotter pin may be bent, as shown, to do the job.

72622

a

b

a - Main Bearing Remover/Installer (J-8080)b - Cotter Pin

3. Rotate the crankshaft clockwise as viewed from the front of engine. This will roll upperbearing out of block.

4. Oil new selected size upper bearing and insert plain (un-notched) end betweencrankshaft and indented or notched side of block. Rotate the bearing into place andremove tool from oil hole in crankshaft journal.

5. Oil new lower bearing and install in bearing cap.

6. Install main bearing cap with arrows pointing toward front of engine.

7. Torque all main bearing caps, EXCEPT THE REAR MAIN CAP, to 75 lb-ft (102 Nm).Torque rear main bearing cap to 10-12 lb-ft (14-16 Nm); then tap end of crankshaft, firstrearward then forward with a lead hammer. This will line up rear main bearing andcrankshaft thrust surfaces. Torque rear main bearing cap to 75 lb-ft (102 Nm).


Page 3A-74 90-861328--1 NOVEMBER 1999

Connecting Rod Bearings

Connecting rod bearings are of the precision insert type and do not use shims foradjustment. DO NOT FILE RODS OR ROD CAPS. If clearances are found to be excessive,a new bearing will be required. Service bearings are available in standard size and .001 in.and .002 in. undersize for use with new and used standard size crankshafts, and in .010 in.and .020 in. undersize for use with reconditioned crankshafts.

On removing a connecting rod cap, it is possible to find a .010 in. undersize bearing. Theseare used in manufacturing for selective fitting.

Inspection and ReplacementIMPORTANT: Before you remove the connecting rod cap, mark the side of the rod andcap with the cylinder number to assure matched reassembly of rod and cap.

1. With oil pan and oil pump removed, remove the connecting rod cap and bearing.

2. Inspect the bearing for evidence of wear and damage. Do not reinstall a worn ordamaged bearing.

3. Wipe both upper and lower bearing shells and crankpin clean of oil.

4. Measure the crankpin for out-of-round or taper with a micrometer. If not withinspecifications, replace or recondition the crankshaft. If within specifications and a newbearing is to be installed, measure the maximum diameter of the crankpin to determinenew bearing size required.

5. If within specifications, measure new or used bearing clearances with gauging plasticor its equivalent. If a bearing is being fitted to an out-of-round crankpin, be sure to fit tothe maximum diameter of the crankpin. If the bearing is fitted to the minimum diameter,and the crankpin is out of round .001 in., interference between the bearing and crankpinwill result in rapid bearing failure.

a. Place a piece of gauging plastic, the length of the bearing (parallel to the crankshaft),on the crankpin or bearing surface as shown. Position the gauging plastic in themiddle of the bearing shell. (Bearings are eccentric and false readings could occurif placed elsewhere.)

72361

a

a - Gauging Plastic

b. Install the bearing in the connecting rod and cap.

c. Install the bearing cap and evenly torque nuts to 45 lb-ft (61 Nm).

IMPORTANT: Do not turn the crankshaft with the gauging plastic installed.


90-861328--1 NOVEMBER 1999 Page 3A-75

d. Remove the bearing cap and using the scale on the gauging plastic envelope,measure the gauging plastic width at the widest point as shown.

72358

a b

6. If the clearance exceeds specifications, select a new, correct size bearing and measurethe clearance.

NOTE: Be sure to check what size bearing is being removed in order to determine properreplacement size bearing. If clearance cannot be brought within specifications, the crankpinwill have to be ground undersize. If the crankpin is already at maximum undersize, replacecrankshaft.

7. Coat the bearing surface with oil, install the rod cap and torque nuts to 45 lb-ft (61 Nm).

8. When all connecting rod bearings have been installed, tap each rod lightly (parallel tothe crankpin) to make sure they have clearance.

9. Measure all connecting rod side clearances between connecting rod caps as shown[Specifications - .006-.014 (0.152-0.356)].

72891


Page 3A-76 90-861328--1 NOVEMBER 1999

Connecting Rod/Piston Assembly

Removal1. Remove oil pan and dipstick tube.

2. Remove oil pump.

76571

3. Remove distributor and intake manifold.

4. Remove cylinder heads.

76576

5. Use a ridge reamer to remove any ridge and/or deposits from upper end of cylinder bore.

IMPORTANT: Before ridge and/or deposits are removed, turn crankshaft until pistonis at bottom of stroke and place a cloth on top of piston to collect cuttings. After ridgeand / or deposits are removed, turn crankshaft until piston is at top of stroke, thenremove cloth and cuttings.

6. Mark connecting rods and bearing caps (left bank 1, 3 and 5; right bank 2, 4 and 6 fromfront to rear on same side as piston thrust).

7. Remove connecting rod cap and install connecting rod bolt guide (3/8-24) on bolts. Pushconnecting rod and piston assembly out of top of cylinder block.


90-861328--1 NOVEMBER 1999 Page 3A-77

NOTE: It will be necessary to turn crankshaft slightly to disconnect and remove someconnecting rod and piston assemblies.

72892

a

a - Connecting Rod Bolt Guide (3/8-24) [J-5239]

DisassemblyDisassemble piston from connecting rod using piston pin remover.

72893

a

b

c

d

e

a - Piston Pin Remover (J-24086-B)b - Arched Basec - Pistond - Connecting Rode - Rod Support


Page 3A-78 90-861328--1 NOVEMBER 1999

Cleaning and Inspection

CONNECTING RODS

1. Wash connecting rods in cleaning solvent and dry with compressed air.

2. Check for twisted and bent rods and inspect for nicks and cracks. Replace damagedconnecting rods.

PISTONS

NOTE: Cylinder bore and taper must be within specifications before pistons can beconsidered for re-use.

1. Clean varnish from piston skirts with a cleaning solvent. DO NOT WIRE BRUSH ANYPART OF PISTON. Clean ring grooves with a groove cleaner and make sure oil ringholes are clean.

2. Inspect piston for damaged ring lands, skirts and pin bosses, wavy or worn ring lands,scuffed or damaged skirts and eroded areas at top of piston.

3. Inspect grooves for nicks and burrs that might cause rings to hang up.

4. Measure piston skirt and check clearance as outlined under “Piston Selection.”

5. Slip outer surface of a new top and second compression ring into respective piston ringgroove and roll ring entirely around the groove to make sure that ring does not bind. Ifring groove causes binding, remove by dressing with a fine cut file. If a distorted ringcauses binding, recheck with another ring.

72894


90-861328--1 NOVEMBER 1999 Page 3A-79

6. Proper clearance of piston ring in its groove is necessary for proper ring action.Therefore, when fitting new rings, clearances between ring and groove surfaces shouldbe measured. See “Specifications.”

72895

PISTON PINS

1. Piston pin clearance is designed to maintain adequate clearance under all engineoperating conditions. Because of this, piston and piston pin are a matched set and notserviced separately.

2. Inspect piston pin bores and piston pins for wear. Piston pin bores and piston pins mustbe free of varnish and scuffing when measured. Measure piston pin with a micrometerand piston pin bore with a dial bore gauge or inside micrometer. If clearance is in excessof the .001 in. (0.02 mm) wear limit, replace piston and piston pin assembly.


Page 3A-80 90-861328--1 NOVEMBER 1999

Reassembly

PISTONS AND PISTON PINS

IMPORTANT: When reassembling pistons and connecting rods, be aware that:

• Piston and pin are machine fitted to each other and must remain together as amatched set. Do not intermix pistons and pins.

• If original pistons and/or connecting rods are being used, be sure to assemblepistons and connecting rods so they can be reinstalled in same cylinder fromwhich they were removed.

• Connecting rod bearing tangs are always toward outside of cylinder block.

72368

a

a - Rod Bearing Tangs

IMPORTANT: Notch in piston must be positioned facing toward the front of theengine.

72896

a

a - Notch


90-861328--1 NOVEMBER 1999 Page 3A-81

1. Assemble piston to connecting rod using piston pin remover as shown. Follow instruc-tions supplied with kit.

72897

a

a - Piston Pin Remover (J-24086-B)

2. Once assembled, check piston for freedom of movement in all directions on connectingrod; piston should move freely. If it does not, piston pin bore is tight and piston/pin as-sembly must be replaced.

3. If a new connecting rod has been installed, mark connecting rod and cap (on side of rodand cap with slots for connecting rod bearing tangs) with cylinder number in which it willbe installed.

PISTON RINGS

All compression rings are marked on upper side of ring. When installing compression rings,make sure that marked side is toward top of piston.

Oil control rings are a three-piece type, consisting of two rings and a spacer.

1. Select rings comparable in size to cylinder bore and piston size.

2. Slip compression ring in cylinder bore, then press ring down into cylinder bore about 1/4in. (6 mm) (below ring travel). Be sure that ring is square with cylinder wall.

3. Measure gap between ends of ring with a feeler gauge as shown.

72372

4. If gap between ends of ring is below specifications, remove ring and try another for fit.

5. Fit each compression ring to cylinder in which it is going to be used.

6. Clean and inspect pistons.


Page 3A-82 90-861328--1 NOVEMBER 1999

7. Install piston rings as follows:

a. Install oil ring spacer in groove and insert anti-rotation tang in oil hole.

b. Hold spacer ends together and install lower steel oil ring rail with gap properly lo-cated.

c. Install upper steel oil ring rail with gap properly located.

d. Flex the oil ring assembly to make sure ring is not binding. If ring groove is causingbinding, remove with a fine cut file. If a distorted ring is causing binding, use a newring.

IMPORTANT: Use piston ring expander (91-24697) for compression ring installation.

e. Install lower compression ring with marked side up, using ring expander.

f. Install top compression ring with marked side up, using ring expander.

InstallationIMPORTANT: Cylinder bores must be clean before piston installation. Clean with alight honing, as necessary. Then clean with hot water and detergent wash. Aftercleaning, swab bores several times with light engine oil and clean cloth, then wipewith a clean dry cloth.

1. Lubricate connecting rod bearings and install in rods and rod caps.

2. Lightly coat pistons, rings and cylinder walls with light engine oil.

3. With bearing caps removed, install connecting rod bolt guide (3/8-24) (J-5239) on con-necting rod bolts.

IMPORTANT: Be sure ring gaps are properly positioned as shown.

72373

a

b

b

c d

e f g

Ring Gap Locationa - Oil Ring Spacer Gap (Tang In Hole Or Slot Within Arc)b - Oil Ring Gapsc - 2nd Compression Ring Gapd - Top Compression Ring Gape - Port Sidef - Engine Frontg - Starboard Side

4. Install each connecting rod and piston assembly in its respective bore. Install withconnecting rod bearing tangs toward outside of cylinder block. Use piston ringcompressor to compress rings. Guide connecting rod into place on crankshaft journalwith connecting rod bolt guide. Use a hammer handle with light blows to install pistoninto bore. Hold ring compressor firmly against cylinder block until all piston rings haveentered cylinder bore.


90-861328--1 NOVEMBER 1999 Page 3A-83

IMPORTANT: Be sure to install new pistons in same cylinders for which they werefitted, and used pistons in same cylinder from which they were removed. Eachconnecting rod and bearing cap should be marked, beginning at front of engine (1,3 and 5 in left bank and 2, 4 and 6 in right bank). Numbers on connecting rod andbearing cap must be on same side when installed in cylinder bore. If a connecting rodis ever transposed from one block or cylinder to another, new bearings should befitted and connecting rod should be numbered to correspond with new cylindernumber.

72552

a

a - Piston Ring Compressor (J-8037)

5. Remove connecting rod bolt guide.

6. Install bearing caps and torque nuts to 20 lb-ft (27 Nm), then tighten nuts an additional70 degrees angular torque using a Torque Angle Gauge.

7. Check connecting rod side clearance.

NOTE: If bearing replacement is required, refer to “Connecting Rod Bearings.”

8. Install oil pump.

a. Install dipstick and oil pan.

b. Install cylinder heads.

c. Install intake manifold.

d. Install distributor.

9. Fill crankcase with oil. Refer to SECTION 1 - “Maintenance.”



Page 3A-84 90-861328--1 NOVEMBER 1999

Crankshaft

Removal1. Remove engine from boat.

2. Drain crankcase oil.

3. Remove starter.

76489

a

b

a - Starterb - Mounting Bolts

4. Remove flywheel housing.

5. Remove drive coupler and flywheel.

76490

a

b

a - Flywheelb - Bolts

6. Remove belts.

7. Remove water pump.

8. Remove crankshaft pulley and torsional damper.

9. Remove spark plugs.

10. Remove oil pan and dipstick tube.

11. Remove oil pump.


90-861328--1 NOVEMBER 1999 Page 3A-85

12. Timing chain cover.

76491

a

a - Timing Chain Gear Cover

13. Turn crankshaft to align timing mark with camshaft mark.

14. Remove camshaft sprocket.

76488

15. Remove rear main seal and retainer.

16. Make sure all bearing caps (main and connecting rods) are marked so they can be rein-stalled in their original locations.

17. Remove connecting rod bearing caps, then push piston and rod assemblies towardheads.

18. Remove main bearing caps and carefully lift crankshaft out of cylinder block.


Page 3A-86 90-861328--1 NOVEMBER 1999

19. If new main and/or connecting rod bearings are to be installed, remove main bearinginserts from cylinder block and bearing caps, and/or connecting rod bearing inserts fromconnecting rod and caps. Install new bearings following procedures outlined.

76582

76581

76579

Cleaning and Inspection1. Wash crankshaft in solvent and dry with compressed air.

2. Measure main bearing journals and crankpin dimensions with a micrometer forout-of-round, taper or undersize. Refer to “Specifications.”

3. Check crankshaft for runout (by supporting at front and rear main bearings journals inV-blocks) and check at front and rear intermediate journals with a dial indicator. Referto “Specifications.”

4. Replace or recondition crankshaft if not within specifications.


90-861328--1 NOVEMBER 1999 Page 3A-87

Installation1. If a new crankshaft is being installed, remove timing sprocket from old crankshaft and

reinstall on new crankshaft as outlined.

IMPORTANT: Be sure that all bearings and crankshaft journals are clean.

2. Install main bearings in engine block as follows.

72359

ab c

Main Bearing Insertsa - Lower Bearing Insert (Install in Cap)b - Upper Bearing Insert (Install in Block)c - Oil Groove

3. Carefully lower crankshaft into place. Be careful not to damage bearing surface.

4. Check clearance of each main bearing. If bearing clearances are satisfactory, apply en-gine oil to journals and bearings.

5. Install main bearing caps. Torque bolts to 75 lb-ft (102 Nm). Refer to “Main Bearings”when tightening rear main bearing cap.

6. Check crankshaft end play.

7. Install rear main seal retainer and seal. Torque fasteners to 133 lb-in. (15 Nm).

8. Check clearance for each connecting rod bearing. If bearing clearances are satisfactory,apply engine oil to journals and bearings.

9. Install rod caps and torque nuts to 45 lb-ft (61 Nm).

10. Reverse Steps 3 - 13 in Removal.

11. Install new oil filter.

12. Fill crankcase with oil.


Page 3A-88 90-861328--1 NOVEMBER 1999

Timing Chain and Sprocket

Removal1. Remove torsional damper, oil pan and crankcase front cover.

2. Turn crankshaft until timing marks on crankshaft and camshaft sprockets are inalignment.

72899

b

a

a - Timing Marks Alignedb - Locating Pin

3. Remove camshaft sprocket and timing chain. (If sprocket does not come off easily, alight tap on the lower edge of the sprocket using a plastic mallet, should dislodge it.)

4. Remove crankshaft sprocket if it requires replacement.

Cleaning and Inspection1. Clean all parts in solvent and dry with compressed air.

2. Inspect timing chain for wear and damage.

3. Inspect sprockets for wear and damage.

Installation - Timing Chain1. Install crankshaft sprocket if removed.

CAUTIONWhen timing marks are aligned in this procedure, the No. 4 cylinder is oncompression (TDC); therefore, if the distributor is to be installed, the rotor MUSTBE positioned at the No. 4 post on the distributor cap.

2. Install timing chain on camshaft sprocket. Hold sprocket vertical with chain hangingdown. Align marks on camshaft and crankshaft sprockets.

IMPORTANT: Do not attempt to drive sprocket on camshaft, as welsh plug at rear ofengine can be dislodged.

3. Install sprocket on camshaft. Torque bolts to 18 lb-ft (24 Nm).

4. Lubricate timing chain with engine oil.

5. Install crankcase front cover and torsional damper.


90-861328--1 NOVEMBER 1999 Page 3A-89

Crankshaft SprocketRemoval

1. Remove torsional damper and crankcase front cover.

2. Remove camshaft timing chain.

3. Using crankshaft gear and sprocket puller (P/N J-5825-A), remove crankshaft sprocket.

Installation1. Using crankshaft gear and sprocket installer, as shown, install sprocket on crankshaft.

72377

a

a - Crankshaft Gear and Sprocket Installer (J-5590)

2. Install timing chain.

3. Install crankcase cover and torsional damper.

Checking Timing Chain DeflectionWith timing chain and sprockets installed, check timing chain deflection, as follows:

1. Rotate camshaft (in either direction) to place tension on one side of the chain.

2. Establish a reference point on the block (on taut side of chain) and measure from thispoint to the chain.

3. Rotate camshaft in the opposite direction to slacken the chain, then force chain out withfingers and again measure the distance between reference point and timing chain.

4. The deflection is the difference between these two measurements. If the deflectionexceeds 3/4 in. (19 mm), timing chain should be replaced.

72899

a

a - Reference Point


Page 3A-90 90-861328--1 NOVEMBER 1999

Balance Shaft / Gears

Removal1. Remove manifold.



76577

3. Remove timing chain.

4. Insert hard wood wedge between gear teeth and remove TORX bolt retaining balanceshaft driven gear. Remove gear.

72900

b

c

a

a - Wedgeb - Driven Gearc - Drive Gear


90-861328--1 NOVEMBER 1999 Page 3A-91

5. Unscrew stud and remove balance shaft drive gear on camshaft as shown.

72901

b

a

a - Studb - Drive Gear

6. Remove two TORX bolts retaining balance shaft thrust plate.

IMPORTANT: Care should be taken in next step as damage to cylinder block and/orbalance shaft could result.

7. Insert pry bar in aft section between balance shaft and cylinder block. Gently apply for-ward pressure and remove balance shaft.

72902

a

b

c

a - Pry Barb - Balance Shaftc - Bearing Housing

NOTE: When replacing balance shaft rear bearing, place a cloth in valley to prevent anydebris from entering the crankcase.


Page 3A-92 90-861328--1 NOVEMBER 1999

8. Balance shaft rear bearing can be replaced using balance shaft removal and installertool in conjunction with bearing puller.

72903

a

b

a - Balance Shaft Removal and Installation Toolb - Bearing Puller

Cleaning and Inspection1. Wash balance shaft in solvent and blow dry with compressed air.

2. Inspect rear bearing for wear or damage. See “Specifications.”

NOTE: Front bearing is not serviceable and may be replaced only with the balance shaftassembly.

3. Inspect front bearing for secure fit on shaft or excessive side to side play. Also checkfor scored bearings or roughness while rotating.

4. Inspect front cylinder block bore for scoring or evidence of bearing spinning in bore.

5. Inspect gears for chips or excessive wear on teeth.

6. Inspect balance shaft gear key way and shaft dowel pin for excessive wear.


90-861328--1 NOVEMBER 1999 Page 3A-93

InstallationNOTE: GM shim (10229872) is placed on installer tool prior to the bearing. This will assureproper depth setting of rear bearing when installed.

1. Use balance shaft remover and installer tool along with GM shim to insert bearing.

76590

2. Lubricate bearings with engine oil and install balance shaft.

3. Using a soft face mallet, tap shaft until front bearing retaining ring seats against cylinderblock.

72904

a

b

a - Retaining Ringb - Cylinder Block

4. Install thrust plate and two TORX bolts. Torque to 120 lb-in. (14 Nm).

5. Install driven gear on balance shaft.


Page 3A-94 90-861328--1 NOVEMBER 1999

6. Align marks on drive and driven gear and install drive gear on camshaft.

72905

a

a - Alignment Marks

7. Install bolts to retain camshaft sprocket and torque to 20 lb-ft (27 Nm).

8. Apply thread adhesive to threads of balance shaft bolt and install.

9. Insert hard wood wedge between gear teeth and torque driven gear retaining bolt to 15lb-ft (20 Nm), then tighten bolt an additional 35 degrees angular torque using a TorqueAngle Gauge.

72906

a

b

a - Wedgeb - Driven Gear

10. Install timing chain.

11. Install crankcase front cover.

12. Install manifold.


90-861328--1 NOVEMBER 1999 Page 3A-95

Camshaft

Measuring Lobe LiftNOTE: Procedure is similar to checking valve timing. If improper valve operation isindicated, measure lift of each push rod in consecutive order and record readings.

1. Remove valve mechanism.

2. Position indicator with ball socket adaptor tool on push rod. Ensuer that push rod is inlifter socket.

72907

a

a - Ball Socket Adaptor Tool (J-8520-1)

3. Rotate crankshaft torsional damper slowly in direction of engine rotation until lifter is onheel of cam lobe. At this point, push rod will be in its lowest position.

4. Set dial indicator on zero, then rotate balancer slowly (or attach an auxiliary starterswitch and “bump” engine over) until push rod is in fully raised position.

5. Compare total lift, recorded from dial indicator, with “Specifications.”

6. Continue to rotate engine until indicator reads zero. This will be a check on accuracy oforiginal indicator reading.

7. If camshaft readings for all lobes are within specifications, remove dial indicatorassembly.

8. Install rocker arm and push rod. Torque nuts to 20 lb-ft (27 Nm).


Page 3A-96 90-861328--1 NOVEMBER 1999

Removal1. Remove valve lifters.

76585



76577

3. Remove camshaft as follows:

a. Remove timing chain, sprocket and camshaft thrust plate.


90-861328--1 NOVEMBER 1999 Page 3A-97

b. Install two 5/16-18 x 5 in. bolts in camshaft bolt holes and carefully remove camshaftas shown.

72908

InspectionMeasure camshaft bearing journals with a micrometer for out-of-round condition. If journalsexceed .001 in. (0.025 mm) out-of-round, camshaft should be replaced.

Also check camshaft for alignment with V-blocks and dial indicator which indicates exactamount camshaft is out of true. If out more than .002 in. (0.05 mm) (dial indicator reading)camshaft should be replaced.

72909

Checking Camshaft Alignment

Installation1. Install camshaft as follows:

a. Install two 5/16-18 x 5 in. bolts in camshaft bolt holes, then lubricate camshaft jour-nals with engine oil and install camshaft. DO NOT damage bearings.

b. Lubricate camshaft lobes with General Motors Cam and Lifter Prelube or equivalent.

c. Install timing chain.

2. Install crankcase front cover and valve lifters.


Page 3A-98 90-861328--1 NOVEMBER 1999

Camshaft Bearings

RemovalCamshaft bearings can be replaced while engine is disassembled for overhaul or withoutcomplete disassembly. To replace bearings without complete disassembly, removecamshaft and crankshaft, leaving cylinder heads attached and pistons in place. Beforeremoving crankshaft, fasten connecting rods against sides of engine so that they will notinterfere while replacing camshaft bearings.

1. With camshaft and crankshaft removed, drive camshaft rear plug from cylinder block.

NOTE: This procedure is based on removal of bearings from center of engine first, thusrequiring a minimum amount of turns to remove all bearings.

2. Using camshaft bearing remover and installer set (J-6098-01) (with nut and thrustwasher installed to end of threads), position pilot in front camshaft bearing and installpuller screw through pilot.

3. Install tool with shoulder toward bearing. Ensure a sufficient amount of threads areengaged.

4. Using two wrenches, hold puller screw while turning nut. When bearing has been pulledfrom bore, remove tool and bearing from puller screw.

5. Remove remaining bearings (except front and rear) in same manner. You must positionpilot in rear camshaft bearing to remove rear intermediate bearing.

72383

c

d

a

b

a - Index Pointb - Puller Screwc - Driverd - Bearing


90-861328--1 NOVEMBER 1999 Page 3A-99

6. Assemble driver on driver handle and remove front and rear camshaft bearings bydriving toward center of cylinder block.

72870

a

b

c

a - Driverb - Driver Handlec - Bearing (Hidden In This View)

InspectionClean camshaft bearing bores in cylinder block with solvent and blow out with compressedair. Be sure grooves and drilled oil passages are clean.

InstallationFront and rear bearings must be installed last as pilot will not fit into bearing bores if bearingsare installed.

Lubricate outer surface of new camshaft bearings with engine oil to ease installation.

IMPORTANT: All camshaft bearings are not the same. Be sure to install bearings inproper locations (Indicated by bearing manufacturer) and to position bearings asfollows (directional references are in reference to engine in its normal operatingposition):

• Front bearing must be positioned so that oil holes are equal distance from 6o’clock position in the block. Intermediate and center bearings must be posi-tioned so that oil holes are at the 5 o’clock position (toward left side of block andat a position even with bottom of cylinder bore). Rear bearing must be positionedso that oil hole is at the 12 o’clock position.

1. Installing intermediate and center bearings:

a. Install nut and thrust washer all the way onto puller screw, then position pilot in frontcamshaft bearing bore and insert screw through pilot.

b. Index center camshaft bearing, then position appropriate size remover and installertool in bearing and thread puller screw into tool. Be sure at least 1/2 in. (13 mm) ofthreads are engaged.

c. Using two wrenches, hold puller screw and turn nut until bearing has been pulled intoposition. Remove the remover and installer tool and check to ensure that oil hole(s)in bearing are positioned correctly.

d. Install intermediate bearings in same manner being sure to index bearings correctly.It will be necessary to position pilot in rear camshaft bearing bore to install rearintermediate bearing.


Page 3A-100 90-861328--1 NOVEMBER 1999

2. Installing front and rear bearings:

a. Install appropriate size remover and installer tool on drive handle.

b. Index front bearing (as explained in “Important” above), and drive it into position withtool. Check position of oil hole(s) in bearing to ensure bearing is positioned correctly.

c. Install rear bearing in same manner, being sure to index bearing correctly.

3. Install a new camshaft rear plug.

IMPORTANT: Plug must be installed flush to 1/32 in. (0.8 mm) deep and must beparallel with rear surface of cylinder block.

4. Install crankshaft and camshaft.

Cylinder Block

Cleaning and Inspection1. Remove all engine components.

2. Wash cylinder block thoroughly in cleaning solvent and clean all gasket surfaces.

3. Remove oil gallery plugs and clean all oil passages.

4. Remove expansion plugs.

NOTE: These plugs may be removed with a sharp punch or they may be drilled and priedout.

5. Clean and inspect water passages in cylinder block.

6. Inspect cylinder block for cracks in cylinder walls, water jacket valve lifter bores and mainbearing webs.


90-861328--1 NOVEMBER 1999 Page 3A-101

7. Measure cylinder walls for taper, out-of-round or excessive ridge at top of ring travel.This should be done with a dial indicator or inside micrometer. Carefully work gauge upand down cylinder to determine taper and turn it to different points around cylinder wallto determine out-of-round condition. If cylinders exceed specifications, boring and/orhoning will be necessary.

72385

a

b

a

b

Cylinder Measurementa - At Right Angle To Centerline Of Engineb - Parallel to Centerline Of Engine

“Out Of Round” Equals The Difference Between “red a” and “red b”

Measurement At Top Of Cylinder Bore andMeasurement At Bottom Of Cylinder Bore

7238672387

Measuring Cylinder Bore Measuring Cylinder Borewith Telescope Gauge with Dial Indicator

8. Check cylinder head gasket surfaces for warp with a machinist’s straight-edge and afeeler gauge. Take measurements diagonally across surfaces (both ways) and straightdown center. If surfaces are warped more than .003 in. (0.07 mm) in a 6 in. area or .007in. (0.2 mm) overall, block must be resurfaced by an automotive machine shop.

72910ab

a - Machinist’s Straight Edgeb - Feeler Gauge


Page 3A-102 90-861328--1 NOVEMBER 1999

CYLINDER CONDITIONING

1. Performance of the following operation depends upon engine condition at time of repair.

2. If cylinder block inspection indicates that block is suitable for continued use (except forout-of-round or tapered cylinders), they can be conditioned by honing or boring.

3. If cylinders have less than .005 in. (0.127 mm) taper or wear, they can be conditionedwith a hone and fitted with high limit standard size piston. A cylinder bore of more than.005 in. wear or taper may not clean up entirely when fitted to a high limit piston. Toentirely clean up the bore, it will be necessary to bore for an oversize piston. If more than.005 in. taper or wear, bore and hone to smallest oversize that will permit completeresurfacing of all cylinders.

4. When pistons are being fitted and honing is not necessary, cylinder bores may becleaned with a hot water and detergent wash. After cleaning, swab cylinder boresseveral times with light engine oil and a clean cloth, then wipe with a clean dry cloth.

CYLINDER BORING

1. Before using a boring bar, file off top of cylinder block to remove dirt or burrs. This is veryimportant to prevent boring bar tilt. Boring bar tilt causes the bored cylinder wall to notbe at right angles to crankshaft.

2. Measure piston to be fitted with a micrometer, measuring at center of piston skirt andat right angles to piston pin. Bore cylinder to same diameter as piston and hone to givespecified clearance.

NOTE: Hone cylinders as outlined under “Cylinder Honing” and “Piston Selection,”following.

3. Carefully observe instructions furnished by manufacturer of equipment being used.

CYLINDER HONING

1. Follow hone manufacturer’s recommendations for use of hone and cleaning andlubrication during honing.

2. Occasionally, during the honing operation, thoroughly clean cylinder bore and checkpiston for correct fit in cylinder.

3. When finish-honing a cylinder bore to fit a piston, move hone up and down at a sufficientspeed to obtain very fine uniform surface finish marks in a crosshatch pattern ofapproximately 30 degrees to cylinder bore. Finish marks should be clean but not sharp,free from imbedded particles and torn or folded metal.

4. Permanently mark piston (for cylinder to which it has been fitted) and proceed to honecylinders and fit remaining pistons.

IMPORTANT: Handle pistons with care and do not attempt to force them throughcylinder until cylinder is honed to correct size, as this type piston can be distortedby careless handling.

5. Thoroughly clean cylinder bores with hot water and detergent. Scrub well with a stiffbristle brush and rinse thoroughly with hot water. It is extremely essential that a goodcleaning operation be performed. If any abrasive material remains in cylinder bores, itwill rapidly wear new rings and cylinder bores in addition to bearings lubricated by thecontaminated oil. Swab bores several times with light engine oil on a clean cloth, thenwipe with a clean dry cloth. Cylinder should not be cleaned with kerosene or gasoline.Clean remainder of cylinder block to remove excess material spread during honingoperation.


90-861328--1 NOVEMBER 1999 Page 3A-103

PISTON SELECTION

1. Check used piston to cylinder bore clearance as follows:

a. Measure cylinder bore diameter with a telescope gauge 2-1/2 in. (64 mm) from topof cylinder bore as shown.

72386

b. Measure piston diameter at skirt across center line of piston pin as shown.

72911

c. Subtract piston diameter from cylinder bore diameter to determine piston-to-boreclearance.

Determine if piston-to-bore clearance is in acceptable “Specifications” range.

2. If used piston is not satisfactory, determine if a new piston can be selected to fit cylinderbore within acceptable range.

3. If cylinder bore must be reconditioned, measure new piston diameter (across centerlineof piston pin), then hone cylinder bore to correct clearance (preferable range).

4. Mark piston to identify cylinder for which it was fitted.


Page 3A-104 90-861328--1 NOVEMBER 1999

Oil Filter By-Pass Valve

Inspection and/or ReplacementOil by-pass valve should be inspected whenever engine is disassembled for major repairor whenever inadequate oil filtration is suspected.

1. Remove oil filter from cylinder block and remove by-pass valve.

2. Clean by-pass valve in solvent and blow dry with compressed air.

3. Inspect fiber valve for cracks or other damage. Ensure that valve fits tightly against itsseat on the seal. Push valve down and release it. Valve should return freely to its seat.If valve operation is questionable, by-pass valve should be replaced.

72912

a

Typical By-Pass Valvea - Fiber Valve

4. Wipe out valve chamber in cylinder block to remove any foreign material.

5. Install by-pass valve and cylinder block adaptor to engine block.

6. Lubricate oil filter rubber seal and install hand-tight only.


90-861328--1 NOVEMBER 1999 Page 3A-105

Remote Oil Filter

Inspection and/or Replacement1. Remove nut from back side of power steering pump bracket.

75010

a

Typicala - Nut

2. The outer oil line on the oil filter housing must be removed in order to install the bracket.

75010

a - Remove This Line

NOTE: Oil lines must be routed under the return line to the power steering pump. Ensurethat the oil lines do not rub or chafe on the exhaust manifold or engine mount.


Page 3A-106 90-861328--1 NOVEMBER 1999

3. Place bracket over the stud and install nut. Torque nut to 12 lb-ft (16 Nm).

75010

a

b

c

a - Bracketb - Nutc - Power Steering Return Line

4. Install bracket screw from the front side of power steering bracket.

75011

a

a - Bracket Screw

5. Install previously removed oil line into oil filter housing. Torque fitting 20 to lb-ft (27 Nm).

6. Lightly lubricate seal on oil filter with engine oil. Install oil filter on oil filter adapter. Handtighten only.

7. Route oil lines past engine mount. Use hose clip to retain hoses. Remove upper screwfrom port side engine mount. Place hose clip over screw and reinstall screw.


90-861328--1 NOVEMBER 1999 Page 3A-107

8. Place the seal in adapter and lightly lubricate with engine oil. Position adaptor over en-gine block and install the bushing in the block. Torque bushing to 40 ft-lb (50 Nm).

75175

a

b

c

d

a - Engine Block To Adapter Sealb - Adapterc - Quad Ringd - Bushing

9. Install oil lines in adapter and orientate as shown. Torque fittings to 20 lb-ft (27 Nm).

75163

a

a - Oil Lines

10. Check oil level and fill if necessary.

11. Start engine and check for oil leaks.


Page 3A-108 90-861328--1 NOVEMBER 1999



90-861328--1 NOVEMBER 1999 Page 3A-109


Mercruiser Service Manual #25 GM V6 1998 - 2001

Documents

andor service

particular service

service trade

manualthis service manual

company service personnel

service procedure andor

special mercury marine

products safety